feat: decouple extension version from CLI version

[jackwener]

Summary

Extension and CLI had tightly coupled version numbers (both bumped to the same value on every release), causing semantic confusion and unnecessary Chrome Web Store submissions. This decouples them so each can release independently.

• Extension version reset to 1.0.0 with independent versioning
• Compatibility protocol: Extension sends compatRange (e.g. >=1.7.0) in its WebSocket hello message; daemon stores it and exposes via /status
• opencli doctor enhanced:
  • Uses compatRange for CLI/extension compatibility checks (falls back to major-version check for older extensions)
  • Shows extension update availability from cached GitHub Releases data
• Release workflow: release.yml now always builds and attaches opencli-extension.zip to every CLI release — users always find both CLI and extension in the same release page
• Build workflow: build-extension.yml triggers on ext-v* tags instead of v* to avoid duplicate builds

Files changed

File	Change
extension/manifest.json	Version → 1.0.0
extension/package.json	Version → 1.0.0, added opencli.compatRange
extension/vite.config.ts	Injects __OPENCLI_COMPAT_RANGE__ at build time
extension/src/background.ts	Hello message includes compatRange
src/daemon.ts	Stores extensionCompatRange, exposes via /status
src/browser/daemon-client.ts	DaemonStatus type includes extensionCompatRange
src/doctor.ts	Compatibility check + extension update check
src/update-check.ts	Caches latest extension version from GitHub Releases
.github/workflows/release.yml	Always attach extension zip
.github/workflows/build-extension.yml	Trigger on ext-v* instead of v*

Test plan

• npx tsc --noEmit — passes (no new TS errors)
• npm test — 196 files, 1487 passed, 2 skipped
• Extension typecheck — same 6 pre-existing errors, no new ones
• CI passes