feat: Electron desktop app, native ffmpeg export, fully static web

- apps/desktop: Electron shell serving the static web build over a
  privileged opencut:// protocol; exports stream frames over IPC to a
  bundled ffmpeg (libx264/libvpx-vp9, BT.709 tagged) with backpressure.
  electron-builder packaging: AppImage, deb, rpm.
- apps/web: dead backend deleted (better-auth, drizzle/pg, upstash,
  botid, freesound proxy, blog, rss, env validation); next build emits
  a zero-env static export; /editor/[project_id] -> /editor?project=.
- Native exporter mirrors SceneExporter; activates when the preload
  bridge is present; web keeps the mediabunny path.
- Docker self-hosting now builds and serves the static export via nginx.
- Release workflow: v* tags publish static web tarball + Linux packages.
- Changelog 0.4.0; README/AGENTS/CONTRIBUTING/roadmap updated.
- GPUI/Rust rewrite parked on branch rust-rewrite.

1 files changed, 28 insertions, 0 deletions

diff --git a/apps/desktop/electron-builder.yml b/apps/desktop/electron-builder.yml
new file mode 100644
index 00000000..b47cf1d7
--- /dev/null
+++ b/apps/desktop/electron-builder.yml
@@ -0,0 +1,28 @@
+appId: rs.cashmere.opencut
+productName: OpenCut
+directories:
+  output: release
+files:
+  - dist/**
+  - package.json
+asarUnpack:
+  - "**/ffmpeg-static/**"
+extraResources:
+  - from: web
+    to: web
+linux:
+  executableName: opencut
+  icon: build/icon.png
+  syncDesktopName: true
+  category: AudioVideo;Video
+  target:
+    - AppImage
+    - deb
+    - rpm
+  artifactName: OpenCut-${version}-linux-${arch}.${ext}
+deb:
+  maintainer: cashmere
+  description: Offline-first video editor
+rpm:
+  maintainer: cashmere
+  description: Offline-first video editor