diff --git a/.claude/helpers/graft-hooks.cjs b/.claude/helpers/graft-hooks.cjs
index aa307ff..6a8a12f 100755
--- a/.claude/helpers/graft-hooks.cjs
+++ b/.claude/helpers/graft-hooks.cjs
@@ -6,7 +6,7 @@ const { execFileSync } = require('child_process');
 const dir = process.env.CLAUDE_PROJECT_DIR || process.cwd();
 const BAKED = "/usr/lib/node_modules/@nanonets/graft/dist/claude";
 
-// The dist/claude dir of @nanonets/graft resolved from a base whose node_modules is searched.
+// dist/claude inside @nanonets/graft, resolved from a directory npm searches.
 function fromPkg(base) {
   try {
     const pkg = require.resolve('@nanonets/graft/package.json', { paths: [base] });
@@ -14,7 +14,7 @@ function fromPkg(base) {
   } catch { return null; }
 }
 
-// The global node_modules dir per npm (handles Homebrew/Windows/volta). Queried on demand.
+// The global node_modules directory, as npm reports it. Queried only when needed.
 function globalRoot() {
   try {
     const root = execFileSync('npm', ['root', '-g'], { encoding: 'utf8', stdio: ['ignore', 'pipe', 'ignore'], shell: process.platform === 'win32' }).trim();
@@ -22,14 +22,14 @@ function globalRoot() {
   } catch { return null; /* npm unavailable */ }
 }
 
-// The version of the package a dist/claude dir belongs to, or null if unreadable.
+// The version of the package that owns a dist/claude directory, or null.
 function versionOf(distClaude) {
   try {
     return JSON.parse(fs.readFileSync(path.join(distClaude, '..', '..', 'package.json'), 'utf8')).version || null;
   } catch { return null; }
 }
 
-// Numeric-dotted compare of the release part; an unreadable version loses to any known one.
+// Compares dotted version numbers. An unreadable version counts as older.
 function newer(a, b) {
   if (!a) return false;
   if (!b) return true;
@@ -42,7 +42,7 @@ function newer(a, b) {
   return false;
 }
 
-// The highest-versioned dir in `dirs` that actually contains `name`, or null.
+// The highest-versioned entry in `dirs` that contains `name`, or null.
 function best(dirs, name) {
   let bestDir = null, bestVer = null;
   for (const d of dirs) {
@@ -54,14 +54,14 @@ function best(dirs, name) {
 }
 
 function entry(name) {
-  // Cheap candidates first, and only shell out to npm when every one of them misses.
+  // Check the cheap candidates first, and run npm only if none of them match.
   const cheap = [BAKED, fromPkg(dir), fromPkg(path.join(path.dirname(process.execPath), '..', 'lib'))];
   const hit = best(cheap, name);
   if (hit) return path.join(hit, name);
   const gr = globalRoot();
   const global = gr && path.join(gr, '@nanonets', 'graft', 'dist', 'claude');
   if (global && fs.existsSync(path.join(global, name))) return path.join(global, name);
-  return path.join(dir, 'dist', 'claude', name); // last-ditch; import will no-op if absent
+  return path.join(dir, 'dist', 'claude', name); // fallback; the import does nothing when the file is absent
 }
 
-import(pathToFileURL(entry("hooks.js")).href).then((m) => m.main(process.argv[2])).catch(() => { /* graft unavailable, no-op */ });
+import(pathToFileURL(entry("hooks.js")).href).then((m) => m.main(process.argv[2])).catch(() => { /* graft is unavailable: do nothing */ });
diff --git a/.claude/helpers/graft-statusline.cjs b/.claude/helpers/graft-statusline.cjs
index ee32aea..7d41b2c 100755
--- a/.claude/helpers/graft-statusline.cjs
+++ b/.claude/helpers/graft-statusline.cjs
@@ -6,7 +6,7 @@ const { execFileSync } = require('child_process');
 const dir = process.env.CLAUDE_PROJECT_DIR || process.cwd();
 const BAKED = "/usr/lib/node_modules/@nanonets/graft/dist/claude";
 
-// The dist/claude dir of @nanonets/graft resolved from a base whose node_modules is searched.
+// dist/claude inside @nanonets/graft, resolved from a directory npm searches.
 function fromPkg(base) {
   try {
     const pkg = require.resolve('@nanonets/graft/package.json', { paths: [base] });
@@ -14,7 +14,7 @@ function fromPkg(base) {
   } catch { return null; }
 }
 
-// The global node_modules dir per npm (handles Homebrew/Windows/volta). Queried on demand.
+// The global node_modules directory, as npm reports it. Queried only when needed.
 function globalRoot() {
   try {
     const root = execFileSync('npm', ['root', '-g'], { encoding: 'utf8', stdio: ['ignore', 'pipe', 'ignore'], shell: process.platform === 'win32' }).trim();
@@ -22,14 +22,14 @@ function globalRoot() {
   } catch { return null; /* npm unavailable */ }
 }
 
-// The version of the package a dist/claude dir belongs to, or null if unreadable.
+// The version of the package that owns a dist/claude directory, or null.
 function versionOf(distClaude) {
   try {
     return JSON.parse(fs.readFileSync(path.join(distClaude, '..', '..', 'package.json'), 'utf8')).version || null;
   } catch { return null; }
 }
 
-// Numeric-dotted compare of the release part; an unreadable version loses to any known one.
+// Compares dotted version numbers. An unreadable version counts as older.
 function newer(a, b) {
   if (!a) return false;
   if (!b) return true;
@@ -42,7 +42,7 @@ function newer(a, b) {
   return false;
 }
 
-// The highest-versioned dir in `dirs` that actually contains `name`, or null.
+// The highest-versioned entry in `dirs` that contains `name`, or null.
 function best(dirs, name) {
   let bestDir = null, bestVer = null;
   for (const d of dirs) {
@@ -54,14 +54,14 @@ function best(dirs, name) {
 }
 
 function entry(name) {
-  // Cheap candidates first, and only shell out to npm when every one of them misses.
+  // Check the cheap candidates first, and run npm only if none of them match.
   const cheap = [BAKED, fromPkg(dir), fromPkg(path.join(path.dirname(process.execPath), '..', 'lib'))];
   const hit = best(cheap, name);
   if (hit) return path.join(hit, name);
   const gr = globalRoot();
   const global = gr && path.join(gr, '@nanonets', 'graft', 'dist', 'claude');
   if (global && fs.existsSync(path.join(global, name))) return path.join(global, name);
-  return path.join(dir, 'dist', 'claude', name); // last-ditch; import will no-op if absent
+  return path.join(dir, 'dist', 'claude', name); // fallback; the import does nothing when the file is absent
 }
 
-import(pathToFileURL(entry("statusline.js")).href).then((m) => m.main()).catch(() => { /* graft unavailable, no-op */ });
+import(pathToFileURL(entry("statusline.js")).href).then((m) => m.main()).catch(() => { /* graft is unavailable: do nothing */ });
diff --git a/.gitignore b/.gitignore
index ef70b62..f0d9dcc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,9 +1,10 @@
-# CMake build directories
+# Build output. /build/ holds the default trees; the other two patterns cover a
+# BUILD_DIR override and the trees that earlier script versions left at the root.
 /build/
 /build_*/
 /cmake-build-*/
 
-# Windows output staging
+# Windows distribution staging
 /SerumAlt_Windows/
 
 # CMake generated files
@@ -12,10 +13,15 @@ compile_commands.json
 
 # IDE and OS files
 .vscode/
-.idea/
+.idea
 *.user
 .DS_Store
 .cache/
 
-# graft's local graph cache — regenerable, not committed (run `graft build`).
+# Upstream JUCE release binaries. They ship with the vendored copy and are not
+# built here; committing them would add 22 MB of Linux executables.
+/third_party/JUCE/DemoRunner
+/third_party/JUCE/Projucer
+
+# graft's local graph cache, regenerable and not committed (run `graft build`).
 /graft/
diff --git a/AGENTS.md b/AGENTS.md
index 320092a..6fb5892 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -62,11 +62,12 @@ safety fixes practical, without adding a generic framework.
 Read README.md's Building section before changing scripts, dependencies, or CMake.
 It is the maintained source for prerequisites, options and artifact paths.
 
-- Linux production: `./build_linux.sh`.
-- macOS production, on a Mac: `./build_macos.sh`.
-- Windows x64 VST3, cross-compiled on Linux: `./build_windows.sh`.
-- Native QA build and execution: `./build_harness.sh --run`.
-- Shell syntax: `for script in build_*.sh; do bash -n "$script"; done`.
+- Linux production: `./scripts/build_linux.sh`.
+- macOS production, on a Mac: `./scripts/build_macos.sh`.
+- Windows x64 VST3, cross-compiled on Linux: `./scripts/build_windows.sh`.
+- Native QA build and execution: `./scripts/build_harness.sh --run`.
+- Shell syntax: `for script in scripts/*.sh; do bash -n "$script"; done`.
+- Build output removal: `./scripts/clean.sh --dry-run`, then the flags you need.
 
 Production scripts explicitly enable `SERUMALT_BUILD_PLUGIN` and disable
 `SERUMALT_BUILD_TESTS`. The harness script does the reverse in a separate directory.
@@ -74,10 +75,11 @@ Building `SerumAltTest` alone does not execute it; `--run` invokes CTest.
 When changing CMake, verify production has no `SerumAltTest` target and the
 harness-only build has no `SerumAlt`, VST3, AU, or Standalone target.
 
-Keep existing build trees and local changes intact. Use a new `BUILD_DIR` for
-clean-build verification. Use a fresh Windows `OUTPUT_DIR` for distribution checks,
-since staging does not remove extra files. Never edit generated CMakeCache.txt files.
-The checked-in MinGW toolchain is the single source of cross-compiler configuration.
+Keep existing build trees and local changes intact. Each script defaults to a
+directory under `build/`; use a new `BUILD_DIR` for clean-build verification. Use a
+fresh Windows `OUTPUT_DIR` for distribution checks, since staging does not remove
+extra files. Never edit generated CMakeCache.txt files. The checked-in
+`cmake/mingw64-toolchain.cmake` is the single source of cross-compiler configuration.
 
 ## Current source layout
 
@@ -95,7 +97,7 @@ The lowercase `Source/engine`, `modulation`, `params`, `plugin`, and `synth`
 directories currently hold guidance, not relocated implementations. Consult their
 `AGENTS.md` files when editing the related root-level sources. Consult the matching
 `AGENTS.md` when editing an existing implementation subdirectory.
-`AUDIT_REPORT.md` is a historical audit and proposed refactor, not a pending
+`docs/AUDIT_REPORT.md` is a historical audit and proposed refactor, not a pending
 instruction to move files. Update the explicit source list and includes only when
 an actual source move is part of the requested task.
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 700ec95..6d02306 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,9 +2,6 @@ cmake_minimum_required(VERSION 3.22)
 
 project(SerumAlt VERSION 1.0.0 LANGUAGES CXX)
 
-# ---------------------------------------------------------------------------
-# C++ standard
-# ---------------------------------------------------------------------------
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -16,9 +13,6 @@ if(NOT SERUMALT_BUILD_PLUGIN AND NOT SERUMALT_BUILD_TESTS)
     message(FATAL_ERROR "Enable SERUMALT_BUILD_PLUGIN or SERUMALT_BUILD_TESTS")
 endif()
 
-# ---------------------------------------------------------------------------
-# JUCE
-# ---------------------------------------------------------------------------
 if(NOT DEFINED JUCE_ROOT)
     set(JUCE_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/third_party/JUCE")
 endif()
@@ -54,7 +48,6 @@ set(SERUMALT_SOURCES
     Source/EffectUnits/Reverb.cpp
     Source/GUI/Knob.cpp
     Source/GUI/KnobLookAndFeel.cpp
-    Source/GUI/Slider.cpp
     Source/GUI/ToggleButton.cpp
     Source/GUI/Display.cpp
     Source/GUI/WaveformDisplay.cpp
diff --git a/README.md b/README.md
index 5c4447d..64db60a 100644
--- a/README.md
+++ b/README.md
@@ -74,14 +74,15 @@ keeps its previous settings if an edit is still in progress.
 
 ## Building
 
-Each script configures and builds its own directory. Production builds disable the
-QA harness explicitly; the harness script creates no plugin or standalone targets.
-JUCE 7.0.12 is vendored under `third_party/JUCE` and is not downloaded by the scripts.
+The scripts live in `scripts/`. Each configures and builds its own directory under
+`build/`. Production builds disable the QA harness explicitly; the harness script
+creates no plugin or standalone targets. JUCE 7.0.12 is vendored under
+`third_party/JUCE` and is not downloaded by the scripts.
 
 ### Prerequisites
 
-All scripts require Bash, CMake 3.22+, Ninja, and C/C++17 compilers. The harness
-also uses CTest, included with CMake, when invoked with `--run`.
+The build scripts require Bash, CMake 3.22+, Ninja, and C/C++17 compilers. The
+harness script also uses CTest, included with CMake, when invoked with `--run`.
 
 On Linux, install GCC or Clang, `pkg-config`, and the ALSA, FreeType, X11 and OpenGL
 development libraries. For Debian/Ubuntu:
@@ -120,40 +121,42 @@ sudo apt install gcc-mingw-w64-x86-64 g++-mingw-w64-x86-64 binutils-mingw-w64-x8
 
 On Arch/CachyOS, use `sudo pacman -S --needed mingw-w64-gcc` instead. Keep the
 native Linux tools and libraries installed: JUCE builds `juceaide` for the host
-before compiling the Windows plugin. The checked-in `mingw64-toolchain.cmake`
+before compiling the Windows plugin. The checked-in `cmake/mingw64-toolchain.cmake`
 selects the `x86_64-w64-mingw32-*` tools and isolates target library searches.
 
 ### Production builds
 
 | Host | Command | Build directory | Formats |
 | --- | --- | --- | --- |
-| Linux | `./build_linux.sh` | `build_linux/` | VST3, Standalone |
-| macOS | `./build_macos.sh` | `build_macos/` | VST3, AU, Standalone |
-| Linux targeting Windows x64 | `./build_windows.sh` | `build_windows/` | VST3 only |
+| Linux | `./scripts/build_linux.sh` | `build/linux/` | VST3, Standalone |
+| macOS | `./scripts/build_macos.sh` | `build/macos/` | VST3, AU, Standalone |
+| Linux targeting Windows x64 | `./scripts/build_windows.sh` | `build/windows/` | VST3 only |
 
 Default Release artifacts:
 
-- Linux: `build_linux/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3` and
-  `build_linux/SerumAlt_artefacts/Release/Standalone/SerumAlt`.
-- macOS: `build_macos/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3`,
-  `build_macos/SerumAlt_artefacts/Release/AU/SerumAlt.component`, and
-  `build_macos/SerumAlt_artefacts/Release/Standalone/SerumAlt.app`.
-- Windows: `build_windows/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3`, also
+- Linux: `build/linux/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3` and
+  `build/linux/SerumAlt_artefacts/Release/Standalone/SerumAlt`.
+- macOS: `build/macos/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3`,
+  `build/macos/SerumAlt_artefacts/Release/AU/SerumAlt.component`, and
+  `build/macos/SerumAlt_artefacts/Release/Standalone/SerumAlt.app`.
+- Windows: `build/windows/SerumAlt_artefacts/Release/VST3/SerumAlt.vst3`, also
   copied to `SerumAlt_Windows/SerumAlt.vst3`.
 
-The Windows script reuses the toolchain file without rewriting it. It injects
-`moduleinfo.json` because the cross-compiled JUCE manifest helper cannot run on
-Linux. Keep this manifest's metadata in sync with `CMakeLists.txt`,
-`cmake/Plugin.cmake`, and the vendored VST3 SDK. MinGW links its C++ and threading
-runtimes statically via `-static-libgcc -static-libstdc++ -static`. Before staging,
-the script verifies the linked module is x86-64, imports none of those MinGW
-runtimes, and exports the VST3 entry points, so a module that a stock Windows host
-could not load fails the build instead of being staged silently.
+The Windows script reuses the toolchain file without rewriting it. A cross-build
+cannot run JUCE's manifest helper, because that helper is a host tool, so the
+script copies the `moduleinfo.json` that CMake writes from
+`cmake/moduleinfo.json.in`. The plugin name, version, vendor, class IDs and VST3
+SDK version come from variables in `cmake/Plugin.cmake`, so a version bump reaches
+the manifest on its own. MinGW links its C++ and threading runtimes statically via
+`-static-libgcc -static-libstdc++ -static`. Before staging, the script verifies the
+linked module is x86-64, imports none of those MinGW runtimes, and exports the VST3
+entry points, so a module that a stock Windows host could not load fails the build
+instead of being staged silently.
 
 macOS builds target the host architecture by default. To request a universal binary:
 
 ```bash
-CMAKE_OSX_ARCHITECTURES='arm64;x86_64' ./build_macos.sh
+CMAKE_OSX_ARCHITECTURES='arm64;x86_64' ./scripts/build_macos.sh
 ```
 
 `CMAKE_OSX_DEPLOYMENT_TARGET` can also be passed to that script. Architecture and
@@ -166,22 +169,22 @@ and do not install plugins into a DAW's plugin directories.
 On Linux or macOS, build the console harness without production targets:
 
 ```bash
-./build_harness.sh
+./scripts/build_harness.sh
 ```
 
 Build and run the checks:
 
 ```bash
-./build_harness.sh --run
+./scripts/build_harness.sh --run
 ```
 
 Or rerun an already-built Release harness:
 
 ```bash
-ctest --test-dir build_harness --build-config Release --output-on-failure --no-tests=error
+ctest --test-dir build/harness --build-config Release --output-on-failure --no-tests=error
 ```
 
-The executable is `build_harness/SerumAltTest_artefacts/Release/SerumAltTest`.
+The executable is `build/harness/SerumAltTest_artefacts/Release/SerumAltTest`.
 It renders the initial state and every factory preset, checks for non-finite
 samples and aggregate non-silence, and exercises the RAVE toggle. A failed check
 returns a nonzero exit status. This is a processor integration smoke test, not a
@@ -204,8 +207,8 @@ library. It is built and run natively, not as a Windows cross-compiled executabl
 For example:
 
 ```bash
-BUILD_TYPE=Debug BUILD_DIR=build_harness_debug ./build_harness.sh --run
-CMAKE_BUILD_PARALLEL_LEVEL=4 ./build_linux.sh
+BUILD_TYPE=Debug BUILD_DIR=build/harness_debug ./scripts/build_harness.sh --run
+CMAKE_BUILD_PARALLEL_LEVEL=4 ./scripts/build_linux.sh
 ```
 
 `CMakeLists.txt` owns the shared source list and target configuration.
@@ -216,9 +219,9 @@ For direct CMake use, `SERUMALT_BUILD_PLUGIN` defaults to `ON` and
 `SERUMALT_BUILD_TESTS` defaults to `OFF`. A harness-only configure is:
 
 ```bash
-cmake -S . -B build_harness -G Ninja -DCMAKE_BUILD_TYPE=Release \
+cmake -S . -B build/harness -G Ninja -DCMAKE_BUILD_TYPE=Release \
     -DSERUMALT_BUILD_PLUGIN=OFF -DSERUMALT_BUILD_TESTS=ON
-cmake --build build_harness --target SerumAltTest
+cmake --build build/harness --target SerumAltTest
 ```
 
 An existing CMake cache retains its old option values; changing the defaults does
@@ -229,12 +232,11 @@ when configuring directly with CMake.
 ### Fresh builds
 
 The scripts reuse their build directories without deleting files, resetting Git,
-or installing packages. Generated `build/`, `build_*/`, and `SerumAlt_Windows/`
-directories are git-ignored. Leave existing builds intact and select an unused
-build directory for a fresh configure:
+or installing packages. `build/` and `SerumAlt_Windows/` are git-ignored. Leave
+existing builds intact and select an unused build directory for a fresh configure:
 
 ```bash
-BUILD_DIR=build_linux_fresh ./build_linux.sh
+BUILD_DIR=build/linux_fresh ./scripts/build_linux.sh
 ```
 
 Windows staging updates generated files without deleting extra files already in
@@ -242,9 +244,27 @@ the destination. For a clean distribution bundle, choose unused build and output
 paths together:
 
 ```bash
-BUILD_DIR=build_windows_fresh OUTPUT_DIR=build_windows_fresh/staged ./build_windows.sh
+BUILD_DIR=build/windows_fresh OUTPUT_DIR=build/windows_fresh/staged ./scripts/build_windows.sh
 ```
 
+### Cleaning
+
+`scripts/clean.sh` removes generated output. A plain run removes the build trees
+under `build/`; `--staging` adds `SerumAlt_Windows/`, `--legacy` adds the
+`build_*` and `cmake-build-*` trees that earlier versions of the scripts left in
+the repository root, and `--all` is both. `--dry-run` prints every path with its
+size and removes nothing.
+
+```bash
+./scripts/clean.sh --dry-run --all
+./scripts/clean.sh --all
+```
+
+The script never removes a tracked file, anything under `Source/`, `third_party/`
+or `.git`, or a path outside the repository. It refuses to run when `BUILD_DIR` or
+`OUTPUT_DIR` names a directory outside the repository, because such a directory
+belongs to another checkout.
+
 ## License
 
 JUCE is licensed separately (see `third_party/JUCE/LICENSE.md`). This project is
diff --git a/Source/GUI/AGENTS.md b/Source/GUI/AGENTS.md
index ffcf603..91ff999 100644
--- a/Source/GUI/AGENTS.md
+++ b/Source/GUI/AGENTS.md
@@ -4,7 +4,7 @@
 
 - Related editor implementation: `../PluginEditor.h`, `../PluginEditor.cpp`
 - Knob.h, Knob.cpp
-- Slider.h, Slider.cpp
+- KnobLookAndFeel.h, KnobLookAndFeel.cpp
 - ToggleButton.h, ToggleButton.cpp
 - Display.h, Display.cpp
 - Panel.h, Panel.cpp
diff --git a/Source/GUI/Slider.cpp b/Source/GUI/Slider.cpp
deleted file mode 100644
index 2b7892c..0000000
--- a/Source/GUI/Slider.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "Slider.h"
-
-namespace serum
-{
-
-Slider::Slider (const juce::String& name, std::function<juce::String (float)> fmt)
-    : Knob (name, std::move (fmt))
-{
-    setSliderStyle (juce::Slider::LinearHorizontal);
-    setTextBoxStyle (juce::Slider::NoTextBox, false, 0, 0);
-}
-
-} // namespace serum
diff --git a/Source/GUI/Slider.h b/Source/GUI/Slider.h
deleted file mode 100644
index 8e0b853..0000000
--- a/Source/GUI/Slider.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#pragma once
-
-#include "Knob.h"
-
-namespace serum
-{
-
-// ===========================================================================
-// Horizontal slider (same formatting machinery as Knob).
-// ===========================================================================
-class Slider : public Knob
-{
-public:
-    explicit Slider (const juce::String& name,
-                     std::function<juce::String (float)> formatter = {});
-};
-
-} // namespace serum
diff --git a/Source/PluginEditor.h b/Source/PluginEditor.h
index c46cf24..9491d87 100644
--- a/Source/PluginEditor.h
+++ b/Source/PluginEditor.h
@@ -3,7 +3,6 @@
 #include <JuceHeader.h>
 #include "PluginProcessor.h"
 #include "GUI/Knob.h"
-#include "GUI/Slider.h"
 #include "GUI/ToggleButton.h"
 #include "GUI/Display.h"
 #include "GUI/Panel.h"
diff --git a/Source/PluginProcessor.h b/Source/PluginProcessor.h
index 4dd1a84..9c870c0 100644
--- a/Source/PluginProcessor.h
+++ b/Source/PluginProcessor.h
@@ -22,6 +22,8 @@ public:
     void prepareToPlay (double sampleRate, int samplesPerBlock) override;
     void releaseResources() override;
     void processBlock (juce::AudioBuffer<float>&, juce::MidiBuffer&) override;
+    // Keeps the base class double-precision overload visible, so it is not hidden.
+    using juce::AudioProcessor::processBlock;
 
     juce::AudioProcessorEditor* createEditor() override;
     bool hasEditor() const override                 { return true; }
diff --git a/Source/Tests/AGENTS.md b/Source/Tests/AGENTS.md
index 275da74..c0d819f 100644
--- a/Source/Tests/AGENTS.md
+++ b/Source/Tests/AGENTS.md
@@ -16,7 +16,7 @@
 ## IF-THEN
 
 - IF a check fails THEN increment the failure count and print the preset name.
-- Build and run natively from the repository root with `./build_harness.sh --run`. Building the `SerumAltTest` target alone does not run checks.
+- Build and run natively from the repository root with `./scripts/build_harness.sh --run`. Building the `SerumAltTest` target alone does not run checks.
 - The harness-only configuration sets `SERUMALT_BUILD_PLUGIN=OFF` and `SERUMALT_BUILD_TESTS=ON`. Production scripts disable the harness.
 - The harness links the real processor and editor sources but creates no plugin bundles. Keep that build separation when adding checks.
 
diff --git a/build_windows.sh b/build_windows.sh
deleted file mode 100755
index 18e7ddf..0000000
--- a/build_windows.sh
+++ /dev/null
@@ -1,167 +0,0 @@
-#!/usr/bin/env bash
-# ---------------------------------------------------------------------------
-# build_windows.sh, cross-compile SerumAlt VST3 for Windows using MinGW-w64
-# ---------------------------------------------------------------------------
-set -euo pipefail
-
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-cd "$SCRIPT_DIR"
-
-TOOLCHAIN_FILE="$SCRIPT_DIR/mingw64-toolchain.cmake"
-BUILD_DIR="${BUILD_DIR:-$SCRIPT_DIR/build_windows}"
-BUILD_TYPE="${BUILD_TYPE:-Release}"
-OUTPUT_DIR="${OUTPUT_DIR:-$SCRIPT_DIR/SerumAlt_Windows}"
-PLUGIN_NAME="SerumAlt"
-export CMAKE_BUILD_PARALLEL_LEVEL="${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
-
-if [[ "$(uname -s)" != Linux ]]; then
-    echo "ERROR: build_windows.sh cross-compiles from Linux using MinGW-w64." >&2
-    exit 1
-fi
-
-# 1. Check for the host tools and MinGW-w64 cross-compiler.
-for tool in cmake ninja pkg-config "${CC:-cc}" "${CXX:-c++}" \
-    x86_64-w64-mingw32-gcc x86_64-w64-mingw32-g++ \
-    x86_64-w64-mingw32-windres x86_64-w64-mingw32-ar \
-    x86_64-w64-mingw32-ranlib x86_64-w64-mingw32-strip \
-    x86_64-w64-mingw32-objdump; do
-    if ! command -v "$tool" >/dev/null 2>&1; then
-        echo "ERROR: $tool not found. See README.md prerequisites." >&2
-        exit 1
-    fi
-done
-
-echo "Found: $(command -v x86_64-w64-mingw32-g++)"
-
-# 2. Use the checked-in CMake toolchain file without overwriting it.
-if [[ ! -f "$TOOLCHAIN_FILE" ]]; then
-    echo "ERROR: Toolchain file not found: $TOOLCHAIN_FILE" >&2
-    exit 1
-fi
-echo "Using toolchain file: $TOOLCHAIN_FILE"
-
-# 3. Configure with CMake + Ninja (VST3-only cross build, no test harness).
-echo "Configuring Windows VST3 in $BUILD_DIR ($BUILD_TYPE)..."
-cmake -S "$SCRIPT_DIR" -B "$BUILD_DIR" -G Ninja \
-    -DCMAKE_BUILD_TYPE="$BUILD_TYPE" \
-    -DCMAKE_TOOLCHAIN_FILE="$TOOLCHAIN_FILE" \
-    -DSERUMALT_BUILD_PLUGIN=ON \
-    -DSERUMALT_BUILD_TESTS=OFF
-
-# 4. Build the VST3 target.
-echo "Building Windows VST3..."
-cmake --build "$BUILD_DIR" --config "$BUILD_TYPE" --target SerumAlt_VST3
-
-# 5. Verify the linked module can load on a stock Windows host.
-#    The MinGW C++/threading runtimes are not part of this bundle and do not exist
-#    on a stock Windows machine, so a module that still imports one of them fails
-#    to load and the host then omits the plugin from its scan list. The static
-#    -runtime link options in cmake/Plugin.cmake are meant to prevent that; check
-#    it here so a stale build tree or a dropped flag fails the build loudly
-#    instead of shipping a bundle that appears nowhere in the host.
-VST3_BUNDLE="$BUILD_DIR/${PLUGIN_NAME}_artefacts/$BUILD_TYPE/VST3/$PLUGIN_NAME.vst3"
-VST3_BINARY="$VST3_BUNDLE/Contents/x86_64-win/$PLUGIN_NAME.vst3"
-if [[ ! -f "$VST3_BINARY" ]]; then
-    echo "ERROR: cross-build produced no module at $VST3_BINARY" >&2
-    exit 1
-fi
-if ! x86_64-w64-mingw32-objdump -f "$VST3_BINARY" | grep -q 'i386:x86-64'; then
-    echo "ERROR: $VST3_BINARY is not an x86-64 module" >&2
-    exit 1
-fi
-VST3_DUMP="$(x86_64-w64-mingw32-objdump -p "$VST3_BINARY")"
-for runtime in libgcc_s_seh-1.dll libstdc++-6.dll libwinpthread-1.dll; do
-    if grep -qF "DLL Name: $runtime" <<<"$VST3_DUMP"; then
-        echo "ERROR: $VST3_BINARY still imports $runtime." >&2
-        echo "       A stock Windows host cannot resolve it and will not list the" >&2
-        echo "       plugin. Restore the static-runtime link options in" >&2
-        echo "       cmake/Plugin.cmake and rebuild with a fresh BUILD_DIR." >&2
-        exit 1
-    fi
-done
-# JUCE implements only these three module entry points on Windows; bundleEntry and
-# bundleExit are macOS-only, and the VST3 SDK's Windows loader requires only
-# GetPluginFactory, treating InitDll/ExitDll as optional.
-for entry in GetPluginFactory InitDll ExitDll; do
-    if ! grep -qE "[[:space:]]${entry}\$" <<<"$VST3_DUMP"; then
-        echo "ERROR: $VST3_BINARY does not export $entry" >&2
-        exit 1
-    fi
-done
-
-# 6. Inject the VST3 moduleinfo.json.
-#    The automatic manifest step is disabled when cross-compiling (see
-#    cmake/Plugin.cmake), because JUCE's manifest helper is a host tool that would
-#    otherwise be built as a Windows executable. The moduleinfo content is
-#    deterministic for this Windows plugin. It depends on the plugin's
-#    name, manufacturer/plugin codes, and version, so we write the same metadata
-#    that the native Windows helper generates. Keep it in sync with the metadata
-#    in CMakeLists.txt and cmake/Plugin.cmake, including the vendored VST3 SDK version.
-echo "Writing Windows VST3 manifest..."
-mkdir -p "$VST3_BUNDLE/Contents/Resources"
-cat > "$VST3_BUNDLE/Contents/Resources/moduleinfo.json" <<'EOF'
-{
-  "Name": "SerumAlt",
-  "Version": "1.0.0",
-  "Factory Info": {
-    "Vendor": "SerumAlt Audio",
-    "URL": "",
-    "E-Mail": "",
-    "Flags": {
-      "Unicode": true,
-      "Classes Discardable": false,
-      "Component Non Discardable": false
-    }
-  },
-  "Classes": [
-    {
-      "CID": "ABCDEF019182FAEB53616C7453657261",
-      "Category": "Audio Module Class",
-      "Name": "SerumAlt",
-      "Vendor": "SerumAlt Audio",
-      "Version": "1.0.0",
-      "SDKVersion": "VST 3.7.8",
-      "Sub Categories": [
-        "Instrument",
-        "Synth"
-      ],
-      "Class Flags": 2,
-      "Cardinality": 2147483647,
-      "Snapshots": []
-    },
-    {
-      "CID": "ABCDEF011234ABCD53616C7453657261",
-      "Category": "Component Controller Class",
-      "Name": "SerumAlt",
-      "Vendor": "SerumAlt Audio",
-      "Version": "1.0.0",
-      "SDKVersion": "VST 3.7.8",
-      "Sub Categories": [
-        "Instrument",
-        "Synth"
-      ],
-      "Class Flags": 2,
-      "Cardinality": 2147483647,
-      "Snapshots": []
-    },
-    {
-      "CID": "ABCDEF01C0DEF00D53616C7453657261",
-      "Category": "Plugin Compatibility Class",
-      "Name": "SerumAlt",
-      "Vendor": "SerumAlt Audio",
-      "Version": "1.0.0",
-      "SDKVersion": "VST 3.7.8",
-      "Class Flags": 0,
-      "Cardinality": 2147483647,
-      "Snapshots": []
-    }
-  ]
-}
-EOF
-
-# 7. Copy the resulting .vst3 bundle to SerumAlt_Windows/ without deleting files.
-echo "Staging Windows VST3 in $OUTPUT_DIR..."
-cmake -E copy_directory "$VST3_BUNDLE" "$OUTPUT_DIR/$PLUGIN_NAME.vst3"
-
-echo
-echo "Done. Windows VST3 plugin at: $OUTPUT_DIR/$PLUGIN_NAME.vst3"
diff --git a/cmake/Harness.cmake b/cmake/Harness.cmake
index b21ac13..639821e 100644
--- a/cmake/Harness.cmake
+++ b/cmake/Harness.cmake
@@ -1,6 +1,4 @@
-# ---------------------------------------------------------------------------
-# Headless QA harness (console app that drives the processor and checks output)
-# ---------------------------------------------------------------------------
+# Headless QA harness: a console app that drives the processor and checks output.
 juce_add_console_app(SerumAltTest)
 serumalt_configure_target(SerumAltTest)
 target_sources(SerumAltTest PRIVATE Source/Tests/TestMain.cpp)
diff --git a/cmake/Plugin.cmake b/cmake/Plugin.cmake
index 45bdf01..871f526 100644
--- a/cmake/Plugin.cmake
+++ b/cmake/Plugin.cmake
@@ -1,14 +1,32 @@
-# ---------------------------------------------------------------------------
-# Plugin target
-# ---------------------------------------------------------------------------
-# JUCE 7.0.12 builds its VST3 manifest helper (juce_vst3_helper) with the same
-# toolchain as the plugin itself. When cross-compiling, that produces a Windows
-# .exe which cannot run on the Linux build host, so we disable the automatic
-# manifest step and inject a Windows moduleinfo.json afterwards
-# (see build_windows.sh). Native builds keep the automatic step.
+# Plugin target.
+
+# Plugin metadata. It lives here once because juce_add_plugin and the cross-build
+# VST3 manifest in cmake/moduleinfo.json.in both need the same values.
+set(SERUMALT_COMPANY_NAME "SerumAlt Audio")
+set(SERUMALT_MANUFACTURER_CODE Salt)
+set(SERUMALT_PLUGIN_CODE Sera)
+set(SERUMALT_VST3_SDK_VERSION "VST 3.7.8") # ships with the vendored JUCE 7.0.12
+
+# VST3 class IDs. Each is a fixed prefix, a per-class constant and the
+# manufacturer and plugin codes as ASCII hex, built the same way JUCE builds
+# them in juce_audio_plugin_client_VST3.cpp.
+string(HEX "${SERUMALT_MANUFACTURER_CODE}${SERUMALT_PLUGIN_CODE}" serumaltCodeHex)
+string(TOUPPER "${serumaltCodeHex}" serumaltCodeHex)
+set(SERUMALT_CID_AUDIO_MODULE "ABCDEF019182FAEB${serumaltCodeHex}")
+set(SERUMALT_CID_CONTROLLER "ABCDEF011234ABCD${serumaltCodeHex}")
+set(SERUMALT_CID_COMPATIBILITY "ABCDEF01C0DEF00D${serumaltCodeHex}")
+
+# JUCE builds its VST3 manifest helper with the target toolchain, so during a
+# Windows cross-build that helper is a Windows .exe and cannot run on the Linux
+# host. Disable the automatic step and write the manifest from the template
+# instead. Native builds keep JUCE's automatic step.
 set(SERUMALT_VST3_AUTO_MANIFEST TRUE)
 if(CMAKE_CROSSCOMPILING)
     set(SERUMALT_VST3_AUTO_MANIFEST FALSE)
+    configure_file(
+        "${CMAKE_CURRENT_SOURCE_DIR}/cmake/moduleinfo.json.in"
+        "${CMAKE_BINARY_DIR}/moduleinfo.json"
+        @ONLY)
 endif()
 
 set(SERUMALT_FORMATS VST3)
@@ -21,14 +39,14 @@ endif()
 
 juce_add_plugin(SerumAlt
     VERSION ${PROJECT_VERSION}
-    COMPANY_NAME "SerumAlt Audio"
+    COMPANY_NAME "${SERUMALT_COMPANY_NAME}"
     IS_SYNTH TRUE
     NEEDS_MIDI_INPUT TRUE
     NEEDS_MIDI_OUTPUT FALSE
     IS_MIDI_EFFECT FALSE
     EDITOR_WANTS_KEYBOARD_FOCUS FALSE
-    PLUGIN_MANUFACTURER_CODE Salt
-    PLUGIN_CODE Sera
+    PLUGIN_MANUFACTURER_CODE ${SERUMALT_MANUFACTURER_CODE}
+    PLUGIN_CODE ${SERUMALT_PLUGIN_CODE}
     BUNDLE_ID com.serumalt.SerumAlt
     FORMATS ${SERUMALT_FORMATS}
     PRODUCT_NAME "SerumAlt"
@@ -36,14 +54,9 @@ juce_add_plugin(SerumAlt
 
 serumalt_configure_target(SerumAlt)
 
-# ---------------------------------------------------------------------------
-# MinGW cross-build: static C++/threading runtime
-# ---------------------------------------------------------------------------
-# When cross-compiling for Windows with MinGW, link libgcc / libstdc++ /
-# winpthread statically so the VST3 DLL is self-contained. Otherwise the DLL
-# imports libgcc_s_seh-1.dll, libstdc++-6.dll and libwinpthread-1.dll, none of
-# which ship with the bundle (or exist on a stock Windows host), so the host's
-# scan would fail to load the plugin. Native (Linux) builds are unaffected.
+# A MinGW cross-build must link libgcc, libstdc++ and winpthread statically.
+# A stock Windows host has none of those DLLs, so a dynamic link produces a
+# module that fails to load and disappears from the host's plugin list.
 if(MINGW)
     target_link_options(SerumAlt_VST3 PRIVATE
         -static-libgcc
diff --git a/mingw64-toolchain.cmake b/cmake/mingw64-toolchain.cmake
similarity index 100%
rename from mingw64-toolchain.cmake
rename to cmake/mingw64-toolchain.cmake
diff --git a/cmake/moduleinfo.json.in b/cmake/moduleinfo.json.in
new file mode 100644
index 0000000..925c13e
--- /dev/null
+++ b/cmake/moduleinfo.json.in
@@ -0,0 +1,57 @@
+{
+  "Name": "@PROJECT_NAME@",
+  "Version": "@PROJECT_VERSION@",
+  "Factory Info": {
+    "Vendor": "@SERUMALT_COMPANY_NAME@",
+    "URL": "",
+    "E-Mail": "",
+    "Flags": {
+      "Unicode": true,
+      "Classes Discardable": false,
+      "Component Non Discardable": false
+    }
+  },
+  "Classes": [
+    {
+      "CID": "@SERUMALT_CID_AUDIO_MODULE@",
+      "Category": "Audio Module Class",
+      "Name": "@PROJECT_NAME@",
+      "Vendor": "@SERUMALT_COMPANY_NAME@",
+      "Version": "@PROJECT_VERSION@",
+      "SDKVersion": "@SERUMALT_VST3_SDK_VERSION@",
+      "Sub Categories": [
+        "Instrument",
+        "Synth"
+      ],
+      "Class Flags": 2,
+      "Cardinality": 2147483647,
+      "Snapshots": []
+    },
+    {
+      "CID": "@SERUMALT_CID_CONTROLLER@",
+      "Category": "Component Controller Class",
+      "Name": "@PROJECT_NAME@",
+      "Vendor": "@SERUMALT_COMPANY_NAME@",
+      "Version": "@PROJECT_VERSION@",
+      "SDKVersion": "@SERUMALT_VST3_SDK_VERSION@",
+      "Sub Categories": [
+        "Instrument",
+        "Synth"
+      ],
+      "Class Flags": 2,
+      "Cardinality": 2147483647,
+      "Snapshots": []
+    },
+    {
+      "CID": "@SERUMALT_CID_COMPATIBILITY@",
+      "Category": "Plugin Compatibility Class",
+      "Name": "@PROJECT_NAME@",
+      "Vendor": "@SERUMALT_COMPANY_NAME@",
+      "Version": "@PROJECT_VERSION@",
+      "SDKVersion": "@SERUMALT_VST3_SDK_VERSION@",
+      "Class Flags": 0,
+      "Cardinality": 2147483647,
+      "Snapshots": []
+    }
+  ]
+}
diff --git a/AUDIT_REPORT.md b/docs/AUDIT_REPORT.md
similarity index 100%
rename from AUDIT_REPORT.md
rename to docs/AUDIT_REPORT.md
diff --git a/UI_UX_AUDIT.md b/docs/UI_UX_AUDIT.md
similarity index 100%
rename from UI_UX_AUDIT.md
rename to docs/UI_UX_AUDIT.md
diff --git a/JANITOR_TASKS.md b/docs/archive/JANITOR_TASKS_2026-05.md
similarity index 100%
rename from JANITOR_TASKS.md
rename to docs/archive/JANITOR_TASKS_2026-05.md
diff --git a/build_harness.sh b/scripts/build_harness.sh
similarity index 73%
rename from build_harness.sh
rename to scripts/build_harness.sh
index 6a71fb4..b035c79 100755
--- a/build_harness.sh
+++ b/scripts/build_harness.sh
@@ -1,10 +1,11 @@
 #!/usr/bin/env bash
+# Build the headless QA harness. Pass --run to execute it through CTest.
 set -euo pipefail
 
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-cd "$SCRIPT_DIR"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
 
-BUILD_DIR="${BUILD_DIR:-$SCRIPT_DIR/build_harness}"
+BUILD_DIR="${BUILD_DIR:-$REPO_ROOT/build/harness}"
 BUILD_TYPE="${BUILD_TYPE:-Release}"
 export CMAKE_BUILD_PARALLEL_LEVEL="${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
 
@@ -17,7 +18,7 @@ TOOLS=(cmake ninja "${CC:-cc}" "${CXX:-c++}")
 case "$(uname -s)" in
     Linux) TOOLS+=(pkg-config) ;;
     Darwin) TOOLS+=(xcrun) ;;
-    *) echo "ERROR: build_harness.sh requires a native Linux or macOS host." >&2; exit 1 ;;
+    *) echo "ERROR: scripts/build_harness.sh requires a Linux or macOS host." >&2; exit 1 ;;
 esac
 if [[ $# -eq 1 ]]; then
     TOOLS+=(ctest)
@@ -33,8 +34,8 @@ if [[ "$(uname -s)" == Darwin ]]; then
     xcrun --sdk macosx --show-sdk-path
 fi
 
-echo "Configuring the native QA harness only in $BUILD_DIR ($BUILD_TYPE)..."
-cmake -S "$SCRIPT_DIR" -B "$BUILD_DIR" -G Ninja \
+echo "Configuring the native QA harness in $BUILD_DIR ($BUILD_TYPE)..."
+cmake -S "$REPO_ROOT" -B "$BUILD_DIR" -G Ninja \
     -DCMAKE_BUILD_TYPE="$BUILD_TYPE" \
     -DSERUMALT_BUILD_PLUGIN=OFF \
     -DSERUMALT_BUILD_TESTS=ON
diff --git a/build_linux.sh b/scripts/build_linux.sh
similarity index 72%
rename from build_linux.sh
rename to scripts/build_linux.sh
index 9579f50..96b8149 100755
--- a/build_linux.sh
+++ b/scripts/build_linux.sh
@@ -1,15 +1,16 @@
 #!/usr/bin/env bash
+# Build the Linux production plugin: VST3 and Standalone.
 set -euo pipefail
 
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-cd "$SCRIPT_DIR"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
 
-BUILD_DIR="${BUILD_DIR:-$SCRIPT_DIR/build_linux}"
+BUILD_DIR="${BUILD_DIR:-$REPO_ROOT/build/linux}"
 BUILD_TYPE="${BUILD_TYPE:-Release}"
 export CMAKE_BUILD_PARALLEL_LEVEL="${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
 
 if [[ "$(uname -s)" != Linux ]]; then
-    echo "ERROR: build_linux.sh requires a Linux host." >&2
+    echo "ERROR: scripts/build_linux.sh requires a Linux host." >&2
     exit 1
 fi
 
@@ -21,7 +22,7 @@ for tool in cmake ninja pkg-config "${CC:-cc}" "${CXX:-c++}"; do
 done
 
 echo "Configuring Linux production targets in $BUILD_DIR ($BUILD_TYPE)..."
-cmake -S "$SCRIPT_DIR" -B "$BUILD_DIR" -G Ninja \
+cmake -S "$REPO_ROOT" -B "$BUILD_DIR" -G Ninja \
     -DCMAKE_BUILD_TYPE="$BUILD_TYPE" \
     -DSERUMALT_BUILD_PLUGIN=ON \
     -DSERUMALT_BUILD_TESTS=OFF
diff --git a/build_macos.sh b/scripts/build_macos.sh
similarity index 78%
rename from build_macos.sh
rename to scripts/build_macos.sh
index 0e6d75e..8f3af6c 100755
--- a/build_macos.sh
+++ b/scripts/build_macos.sh
@@ -1,15 +1,16 @@
 #!/usr/bin/env bash
+# Build the macOS production plugin: VST3, AU and Standalone.
 set -euo pipefail
 
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-cd "$SCRIPT_DIR"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
 
-BUILD_DIR="${BUILD_DIR:-$SCRIPT_DIR/build_macos}"
+BUILD_DIR="${BUILD_DIR:-$REPO_ROOT/build/macos}"
 BUILD_TYPE="${BUILD_TYPE:-Release}"
 export CMAKE_BUILD_PARALLEL_LEVEL="${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
 
 if [[ "$(uname -s)" != Darwin ]]; then
-    echo "ERROR: build_macos.sh requires macOS and the Apple SDK." >&2
+    echo "ERROR: scripts/build_macos.sh requires macOS and the Apple SDK." >&2
     exit 1
 fi
 
@@ -30,7 +31,7 @@ if [[ -n "${CMAKE_OSX_DEPLOYMENT_TARGET:-}" ]]; then
 fi
 
 echo "Configuring macOS production targets in $BUILD_DIR ($BUILD_TYPE)..."
-cmake -S "$SCRIPT_DIR" -B "$BUILD_DIR" -G Ninja \
+cmake -S "$REPO_ROOT" -B "$BUILD_DIR" -G Ninja \
     "${OSX_OPTIONS[@]}" \
     -DSERUMALT_BUILD_PLUGIN=ON \
     -DSERUMALT_BUILD_TESTS=OFF
diff --git a/scripts/build_windows.sh b/scripts/build_windows.sh
new file mode 100755
index 0000000..31a7a8c
--- /dev/null
+++ b/scripts/build_windows.sh
@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+# Cross-compile the Windows x64 VST3 from Linux with MinGW-w64.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+TOOLCHAIN_FILE="$REPO_ROOT/cmake/mingw64-toolchain.cmake"
+BUILD_DIR="${BUILD_DIR:-$REPO_ROOT/build/windows}"
+BUILD_TYPE="${BUILD_TYPE:-Release}"
+OUTPUT_DIR="${OUTPUT_DIR:-$REPO_ROOT/SerumAlt_Windows}"
+PLUGIN_NAME="SerumAlt"
+export CMAKE_BUILD_PARALLEL_LEVEL="${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
+
+if [[ "$(uname -s)" != Linux ]]; then
+    echo "ERROR: scripts/build_windows.sh cross-compiles from Linux with MinGW-w64." >&2
+    exit 1
+fi
+
+for tool in cmake ninja pkg-config "${CC:-cc}" "${CXX:-c++}" \
+    x86_64-w64-mingw32-gcc x86_64-w64-mingw32-g++ \
+    x86_64-w64-mingw32-windres x86_64-w64-mingw32-ar \
+    x86_64-w64-mingw32-ranlib x86_64-w64-mingw32-strip \
+    x86_64-w64-mingw32-objdump; do
+    if ! command -v "$tool" >/dev/null 2>&1; then
+        echo "ERROR: $tool not found. See README.md prerequisites." >&2
+        exit 1
+    fi
+done
+
+if [[ ! -f "$TOOLCHAIN_FILE" ]]; then
+    echo "ERROR: toolchain file not found: $TOOLCHAIN_FILE" >&2
+    exit 1
+fi
+
+echo "Configuring Windows VST3 in $BUILD_DIR ($BUILD_TYPE)..."
+cmake -S "$REPO_ROOT" -B "$BUILD_DIR" -G Ninja \
+    -DCMAKE_BUILD_TYPE="$BUILD_TYPE" \
+    -DCMAKE_TOOLCHAIN_FILE="$TOOLCHAIN_FILE" \
+    -DSERUMALT_BUILD_PLUGIN=ON \
+    -DSERUMALT_BUILD_TESTS=OFF
+
+echo "Building Windows VST3..."
+cmake --build "$BUILD_DIR" --config "$BUILD_TYPE" --target SerumAlt_VST3
+
+# A stock Windows host has neither the MinGW C++ runtime nor the MinGW threading
+# runtime, so a module that imports one fails to load and the host drops it from
+# its plugin list. cmake/Plugin.cmake links both statically; these checks fail the
+# build when that link option is missing from a cached or a fresh build tree.
+VST3_BUNDLE="$BUILD_DIR/${PLUGIN_NAME}_artefacts/$BUILD_TYPE/VST3/$PLUGIN_NAME.vst3"
+VST3_BINARY="$VST3_BUNDLE/Contents/x86_64-win/$PLUGIN_NAME.vst3"
+if [[ ! -f "$VST3_BINARY" ]]; then
+    echo "ERROR: cross-build produced no module at $VST3_BINARY" >&2
+    exit 1
+fi
+if ! x86_64-w64-mingw32-objdump -f "$VST3_BINARY" | grep -q 'i386:x86-64'; then
+    echo "ERROR: $VST3_BINARY is not an x86-64 module" >&2
+    exit 1
+fi
+VST3_DUMP="$(x86_64-w64-mingw32-objdump -p "$VST3_BINARY")"
+for runtime in libgcc_s_seh-1.dll libstdc++-6.dll libwinpthread-1.dll; do
+    if grep -qF "DLL Name: $runtime" <<<"$VST3_DUMP"; then
+        echo "ERROR: $VST3_BINARY still imports $runtime." >&2
+        echo "       Restore the static-runtime link options in cmake/Plugin.cmake" >&2
+        echo "       and rebuild with a fresh BUILD_DIR." >&2
+        exit 1
+    fi
+done
+# JUCE defines only these entry points on Windows. bundleEntry and bundleExit are
+# macOS-only, and the VST3 SDK loader requires GetPluginFactory while treating
+# InitDll and ExitDll as optional.
+for entry in GetPluginFactory InitDll ExitDll; do
+    if ! grep -qE "[[:space:]]${entry}\$" <<<"$VST3_DUMP"; then
+        echo "ERROR: $VST3_BINARY does not export $entry" >&2
+        exit 1
+    fi
+done
+
+# JUCE's manifest helper is a host tool, so a cross-build disables it and CMake
+# writes moduleinfo.json from cmake/moduleinfo.json.in instead.
+MANIFEST="$BUILD_DIR/moduleinfo.json"
+if [[ ! -f "$MANIFEST" ]]; then
+    echo "ERROR: CMake wrote no manifest at $MANIFEST" >&2
+    exit 1
+fi
+mkdir -p "$VST3_BUNDLE/Contents/Resources"
+cmake -E copy "$MANIFEST" "$VST3_BUNDLE/Contents/Resources/moduleinfo.json"
+
+echo "Staging Windows VST3 in $OUTPUT_DIR..."
+cmake -E copy_directory "$VST3_BUNDLE" "$OUTPUT_DIR/$PLUGIN_NAME.vst3"
+
+echo
+echo "Done. Windows VST3 plugin at: $OUTPUT_DIR/$PLUGIN_NAME.vst3"
diff --git a/scripts/clean.sh b/scripts/clean.sh
new file mode 100755
index 0000000..df8b04c
--- /dev/null
+++ b/scripts/clean.sh
@@ -0,0 +1,137 @@
+#!/usr/bin/env bash
+# Remove generated build output from this checkout.
+#
+# Targets are limited to directories this project generates. Nothing tracked by
+# git is removed, and Source/, third_party/, .git and the other project
+# directories are refused even if they are named as a target.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+usage() {
+    cat <<'EOF'
+Usage: scripts/clean.sh [options]
+
+Removes generated build output. With no options it removes the build trees
+under build/.
+
+Options:
+  --staging   also remove the staged Windows bundle, SerumAlt_Windows/
+  --legacy    also remove build trees left in the repository root by earlier
+              versions of the build scripts (build_*, cmake-build-*)
+  --all       --staging and --legacy together
+  --dry-run   print every path and its size, and remove nothing
+  -h, --help  print this text
+EOF
+}
+
+DRY_RUN=false
+STAGING=false
+LEGACY=false
+for arg in "$@"; do
+    case "$arg" in
+        --dry-run) DRY_RUN=true ;;
+        --staging) STAGING=true ;;
+        --legacy) LEGACY=true ;;
+        --all) STAGING=true; LEGACY=true ;;
+        -h|--help) usage; exit 0 ;;
+        *) echo "ERROR: unknown option: $arg" >&2; usage >&2; exit 2 ;;
+    esac
+done
+
+if ! command -v git >/dev/null 2>&1; then
+    echo "ERROR: git is required to confirm that no tracked file is removed." >&2
+    exit 2
+fi
+
+# A build directory outside the repository belongs to some other checkout, and
+# this script has no business deciding whether it is disposable.
+for var in BUILD_DIR OUTPUT_DIR; do
+    value="${!var:-}"
+    [ -n "$value" ] || continue
+    case "$value" in
+        /*) abs="$value" ;;
+        *) abs="$REPO_ROOT/$value" ;;
+    esac
+    abs="$(realpath -m -- "$abs" 2>/dev/null || printf '%s' "$abs")"
+    case "$abs" in
+        "$REPO_ROOT"/*) ;;
+        *)
+            echo "ERROR: $var=$value resolves outside $REPO_ROOT." >&2
+            echo "       Unset $var to clean this repository." >&2
+            exit 2
+            ;;
+    esac
+done
+
+PROTECTED=(Source third_party .git scripts cmake docs graft)
+
+refused=0
+removed=0
+
+remove_target() {
+    local path="$1"
+    [ -e "$path" ] || return 0
+
+    local abs rel size
+    abs="$(realpath -m -- "$path")"
+    rel="${abs#"$REPO_ROOT"/}"
+
+    case "$abs" in
+        "$REPO_ROOT"/*) ;;
+        *)
+            echo "refusing, outside the repository: $abs" >&2
+            refused=$((refused + 1))
+            return 1
+            ;;
+    esac
+
+    local deny
+    for deny in "${PROTECTED[@]}"; do
+        if [ "$rel" = "$deny" ] || [ "${rel#"$deny"/}" != "$rel" ]; then
+            echo "refusing, protected path: $rel" >&2
+            refused=$((refused + 1))
+            return 1
+        fi
+    done
+
+    if [ -n "$(git ls-files -- "$rel")" ]; then
+        echo "refusing, tracked by git: $rel" >&2
+        refused=$((refused + 1))
+        return 1
+    fi
+
+    size="$(du -sh -- "$rel" 2>/dev/null | cut -f1)"
+    if [ "$DRY_RUN" = true ]; then
+        printf 'would remove  %6s  %s\n' "${size:-?}" "$rel"
+    else
+        rm -rf -- "$abs"
+        printf 'removed       %6s  %s\n' "${size:-?}" "$rel"
+    fi
+    removed=$((removed + 1))
+}
+
+TARGETS=("$REPO_ROOT/build")
+if [ "$STAGING" = true ]; then
+    TARGETS+=("$REPO_ROOT/SerumAlt_Windows")
+fi
+if [ "$LEGACY" = true ]; then
+    shopt -s nullglob
+    for dir in "$REPO_ROOT"/build_* "$REPO_ROOT"/cmake-build-*; do
+        TARGETS+=("$dir")
+    done
+    shopt -u nullglob
+fi
+
+for target in "${TARGETS[@]}"; do
+    remove_target "$target" || true
+done
+
+if [ "$removed" -eq 0 ] && [ "$refused" -eq 0 ]; then
+    echo "Nothing to remove."
+elif [ "$DRY_RUN" = true ]; then
+    echo "Dry run: $removed path(s) listed, nothing removed."
+fi
+
+[ "$refused" -eq 0 ]