Debian support: verified build/packaging path + friend install guide

- setup-standalone.sh: falls back to system python3 -m venv + pip when
  uv isn't installed (Debian/Ubuntu path; verified on clean bookworm).
- dist/Dockerfile.debian: debian:bookworm build env for :app:packageDeb
  (needs fakeroot + /usr/share/desktop-directories — both baked in; the
  dir gap made jpackage's postinst fail with exit 3 on minimal systems).
- dist/make-release.sh: clean source tarball from HEAD.
- INSTALL-debian.md: end-to-end install for friends (source tree must
  stay on disk — the app spawns the engine from it via SHONAR_REPO).

Verified on real Debian 12 in Docker: :app:packageDeb builds
shonar-desktop_0.1.0-1_amd64.deb, apt installs it, setup-standalone.sh
provisions the engine (venv+pip path, model fetch, boot smoke test),
and the packaged binary launches under Xvfb.

INSTALL-debian.md

@@ -0,0 +1,54 @@
+# SHONAR Desktop — installing on Debian (12/13) or Ubuntu
+
+Everything runs locally on your machine. No accounts, no cloud, no
+telemetry. Audio, transcripts, and settings never leave your computer.
+
+There are two pieces: the **desktop app** (browse, transcribe, search)
+and the **transcription engine** (faster-whisper, bundled model — works
+offline after setup).
+
+## 1. Put the source tree where the app can find it
+
+The app auto-starts the bundled engine from the source folder, so keep
+the unpacked tarball around. Either:
+
+    mkdir -p ~/Projects && tar xzf shonar-desktop-*.tar.gz -C ~/Projects \
+      && mv ~/Projects/shonar-desktop-* ~/Projects/"Shonar Desktop"
+
+or extract anywhere and export `SHONAR_REPO=/that/path` (add it to
+`~/.profile`, or to the desktop launcher's Environment= line).
+
+## 2. Install the app
+
+Option A — .deb package (if you got `shonar-desktop_*.deb`):
+
+    sudo apt install ./shonar-desktop_0.1.0_amd64.deb
+    shonar-desktop
+
+Option B — run straight from the source tree (needs JDK 17, step 3):
+
+    cd ~/Projects/"Shonar Desktop" && ./launch-desktop.sh
+
+## 3. One-time setup
+
+    sudo apt install -y openjdk-17-jdk python3 python3-venv mpv
+    cd ~/Projects/"Shonar Desktop" && ./setup-standalone.sh
+
+This creates the engine's Python environment, vendors the whisper
+"base" model into `models/hf-cache` (one-time download, ~142 MB), and
+boots the engine once to prove it works.
+
+## 4. Run it
+
+Launch `shonar-desktop` (menu entry) or `./launch-desktop.sh`.
+The app starts the engine itself on first launch (takes a few seconds).
+Point "Choose folder…" at the folder holding your recordings and go.
+
+Notes
+- mpv is used for click-to-play from search results.
+- Summaries: if you run [Ollama](https://ollama.com) locally the app
+  uses it automatically; without it, transcription still works and
+  summaries are simply skipped.
+- Engine logs: `~/.config/shonar-desktop/engine.log`.
+- Wayland/Hyprland works; on X11 set nothing special.
+- Ctrl+= / Ctrl+- zooms the whole app; Ctrl+0 resets.