docs: document wails3 development and distribution

Replace the NPM-first workflow with Wails v3 dev and build instructions,
including platform prerequisites for macOS and Windows.

Co-authored-by: Cursor <cursoragent@cursor.com>

README.md

@@ -4,37 +4,63 @@ Annotate keyboard key presses on a video timeline and preview/export mechanical
 
 Keyboard sounds are sourced from [kbsim](https://github.com/tplai/kbsim) (MIT license) — recorded press and release samples with per-key variation.
 
+sfxkeeb is a **Wails v3 desktop app** (Go shell + Svelte frontend). Native file dialogs are used for opening videos/projects and saving exports.
+
 ## Requirements
 
-- Node.js 18+ and npm
+- **Go** 1.22+
+- **Wails v3 CLI**: `go install github.com/wailsapp/wails/v3/cmd/wails3@latest`
+- **Node.js** 18+ and npm
 - **git** (to fetch kbsim sample assets)
 
+### Platform tooling
+
+| Platform | Additional requirements |
+| -------- | ----------------------- |
+| macOS    | Xcode Command Line Tools |
+| Windows  | [WebView2 runtime](https://developer.microsoft.com/en-us/microsoft-edge/webview2/) (usually pre-installed on Windows 11); build tools for `wails3 task build` |
+
 ## Setup
 
 ```bash
 # Frontend dependencies
 cd frontend && npm install
+
+# Download kbsim switch samples (~151 MP3 files)
+cd .. && ./scripts/fetch_kbsim_samples.sh
 ```
 
 ## Development
 
-```bash
-cd frontend && npm run dev
-```
-
-Open http://localhost:5173
-
-## Production
+From the repository root:
 
 ```bash
-cd frontend && npm run build && npm run preview
+wails3 dev
 ```
 
-Or serve `frontend/dist` with any static file host.
+This builds the Go backend, starts the Vite dev server, and opens the desktop window. File I/O uses native dialogs via Wails bindings.
+
+For frontend-only work (no Wails bindings), you can still run `cd frontend && npm run dev`, but open/save dialogs will not function outside the Wails shell.
+
+## Production build
+
+From the repository root:
+
+```bash
+wails3 task build
+```
+
+The compiled binary is written to `bin/sfxkeeb`. On macOS, package a `.app` bundle with:
+
+```bash
+wails3 task package
+```
+
+Build on each target platform (macOS for `.app`, Windows for `.exe`). Windows users need the WebView2 runtime installed.
 
 ## Usage
 
-1. **Open Video** — load an MP4 file
+1. **Open Video** — pick an MP4 (or other supported video) via native file dialog
 2. Press keys while the playhead is at the desired time to add markers (works while playing or paused)
    - Press sound plays on keydown; release sound plays on keyup
    - Each physical key maps to a stable press variant (same key always sounds the same)
@@ -42,7 +68,7 @@ Or serve `frontend/dist` with any static file host.
 4. Choose a mechanical switch sound from the dropdown (13 kbsim profiles)
 5. Adjust preview speed (25–200%) for fast-paced content — preview only; export is always at 1×
 6. **Save Project** / **Open Project** — JSON with version, markers, and switch setting (no video path)
-7. **Export Audio** — download a WAV file of keyboard sounds only, full video length (rendered client-side)
+7. **Export Audio** — save a WAV file of keyboard sounds only, full video length (rendered client-side)
 
 ### Keyboard shortcuts