feat(macos): add Sparkle updates and release docs

docs/mac/release.md

@@ -0,0 +1,67 @@
+---
+summary: "Clawdis macOS release checklist (Sparkle feed, packaging, signing)"
+read_when:
+  - Cutting or validating a Clawdis macOS release
+  - Updating the Sparkle appcast or feed assets
+---
+
+# Clawdis macOS release (Sparkle)
+
+This app now ships Sparkle auto-updates. Release builds must be Developer ID–signed, zipped, and published with a signed appcast entry.
+
+## Prereqs
+- Developer ID Application cert installed (`Developer ID Application: Peter Steinberger (Y5PE65HELJ)` is expected).
+- Sparkle private key path set in the environment as `SPARKLE_PRIVATE_KEY_FILE`; key lives in `/Users/steipete/Library/CloudStorage/Dropbox/Backup/Sparkle` (same key as Trimmy; public key baked into Info.plist).
+- `pnpm` deps installed (`pnpm install --config.node-linker=hoisted`).
+- Sparkle tools are fetched automatically via SwiftPM at `apps/macos/.build/artifacts/sparkle/Sparkle/bin/` (`sign_update`, `generate_appcast`, etc.).
+
+## Build & package
+```bash
+# From repo root; set release IDs so Sparkle feed is enabled
+BUNDLE_ID=com.steipete.clawdis \
+APP_VERSION=0.1.0 \
+APP_BUILD=0.1.0 \
+BUILD_CONFIG=release \
+SIGN_IDENTITY="Developer ID Application: Peter Steinberger (Y5PE65HELJ)" \
+scripts/package-mac-app.sh
+
+# Zip for distribution (includes resource forks for Sparkle delta support)
+ditto -c -k --sequesterRsrc --keepParent dist/Clawdis.app dist/Clawdis-0.1.0.zip
+
+# Optional: ship dSYM alongside the release
+ditto -c -k --keepParent apps/macos/.build/release/Clawdis.app.dSYM dist/Clawdis-0.1.0.dSYM.zip
+```
+
+## Appcast entry
+1. Generate the ed25519 signature (requires `SPARKLE_PRIVATE_KEY_FILE`):
+   ```bash
+   SPARKLE_PRIVATE_KEY_FILE=/Users/steipete/Library/CloudStorage/Dropbox/Backup/Sparkle/ed25519-private-key \
+   apps/macos/.build/artifacts/sparkle/Sparkle/bin/sign_update dist/Clawdis-0.1.0.zip
+   ```
+   Copy the reported signature and file size.
+2. Edit `appcast.xml` (root of repo), add a new `<item>` at the top pointing to the GitHub release asset. Example snippet to adapt:
+   ```xml
+   <item>
+     <title>Clawdis 0.1.0</title>
+     <sparkle:releaseNotesLink>https://github.com/steipete/clawdis/releases/tag/v0.1.0</sparkle:releaseNotesLink>
+     <pubDate>Sun, 07 Dec 2025 12:00:00 +0000</pubDate>
+     <enclosure url="https://github.com/steipete/clawdis/releases/download/v0.1.0/Clawdis-0.1.0.zip"
+                sparkle:edSignature="<signature from sign_update>"
+                sparkle:version="0.1.0"
+                sparkle:shortVersionString="0.1.0"
+                length="<zip byte size>"
+                type="application/octet-stream" />
+   </item>
+   ```
+   Keep the newest item first; leave the channel metadata intact.
+3. Commit the updated `appcast.xml` alongside the release assets (zip + dSYM) when publishing.
+
+## Publish & verify
+- Upload `Clawdis-0.1.0.zip` (and `Clawdis-0.1.0.dSYM.zip`) to the GitHub release for tag `v0.1.0`.
+- Ensure the raw appcast URL matches the baked feed: `https://raw.githubusercontent.com/steipete/clawdis/main/appcast.xml`.
+- Sanity checks:
+  - `curl -I https://raw.githubusercontent.com/steipete/clawdis/main/appcast.xml` returns 200.
+  - `curl -I <enclosure url>` returns 200 after assets upload.
+  - On a previous public build, run “Check for Updates…” from the About tab and verify Sparkle installs the new build cleanly.
+
+Definition of done: signed app + appcast are published, update flow works from an older installed version, and release assets are attached to the GitHub release.