feat: version-aware find-browse with META signal protocol

Agents in other workspaces found stale browse binaries that were missing
newer flags. find-browse now compares the local binary's git SHA against
origin/main via git ls-remote (4hr cache), and emits META:UPDATE_AVAILABLE
when behind. SKILL.md setup checks parse META signals and prompt the user
to update.

- New compiled binary: browse/dist/find-browse (TypeScript, testable)
- Bash shim at browse/bin/find-browse delegates to compiled binary
- .version file written at build time with git commit SHA
- Build script compiles both browse and find-browse binaries
- Graceful degradation: offline, missing .version, corrupt cache all skip check

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

setup-browser-cookies/SKILL.md

@@ -26,9 +26,12 @@ Import logged-in sessions from your real Chromium browser into the headless brow
 ### 1. Find the browse binary
 
 ```bash
-B=$(browse/bin/find-browse 2>/dev/null || ~/.claude/skills/gstack/browse/bin/find-browse 2>/dev/null)
+BROWSE_OUTPUT=$(browse/bin/find-browse 2>/dev/null || ~/.claude/skills/gstack/browse/bin/find-browse 2>/dev/null)
+B=$(echo "$BROWSE_OUTPUT" | head -1)
+META=$(echo "$BROWSE_OUTPUT" | grep "^META:" || true)
 if [ -n "$B" ]; then
   echo "READY: $B"
+  [ -n "$META" ] && echo "$META"
 else
   echo "NEEDS_SETUP"
 fi
@@ -39,6 +42,8 @@ If `NEEDS_SETUP`:
 2. Run: `cd <SKILL_DIR> && ./setup`
 3. If `bun` is not installed: `curl -fsSL https://bun.sh/install | bash`
 
+If you see `META:UPDATE_AVAILABLE`: tell the user an update is available, STOP and wait for approval, then run the command from the META payload and re-run the setup check.
+
 ### 2. Open the cookie picker
 
 ```bash