feat: migrate to openrouter.ai/labs/spawn CDN + release artifact version checks (#2178)

* feat: migrate shell script URLs to openrouter.ai/labs/spawn CDN

Users on older CLI versions can't auto-update because the repo was restructured
(cli/ → packages/cli/), so old version-check URLs 404. This decouples the CLI
from the repo's internal directory structure:

- Shell script URLs (install, agent scripts, github-auth) now use
  openrouter.ai/labs/spawn/* as primary with GitHub raw as fallback
- Version checks now use GitHub release artifact (cli-latest/version)
  as primary — a static URL that never changes regardless of repo layout
- CI workflow updated to publish a `version` file alongside cli.js
- Remove GITHUB_RAW_URL_PATTERN validation (no longer needed since
  install URL is now a hardcoded CDN string, not interpolated)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* style: fix biome formatting in update-check test

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: CLAUDE.md says biome lint but should say biome check

biome lint only checks lint rules, not formatting. biome check does both.
The hooks and CI already run biome check — the docs were out of sync.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(hooks): PostToolUse hook wasn't running biome on CLI source files

Two bugs in validate-file.ts:

1. Config search only checked 1-2 levels up from the edited file, but
   biome.json is at packages/cli/ — 3 levels above src/__tests__/*.ts.
   Fix: walk up directories until biome.json is found (or hit root).

2. Ran `biome format` (prints formatted output, always exits 0) instead
   of `biome format --check` (exits non-zero if file needs formatting).
   Fix: use `biome check` which does lint + format check in one pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/cli-release.yml

@@ -41,6 +41,10 @@ jobs:
         working-directory: packages/cli
         run: echo "version=$(jq -r .version package.json)" >> "$GITHUB_OUTPUT"
 
+      - name: Create version file
+        working-directory: packages/cli
+        run: jq -r .version package.json > version
+
       - name: Update cli-latest release
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -50,17 +54,19 @@ jobs:
           git tag -d cli-latest 2>/dev/null || true
           git push origin :refs/tags/cli-latest 2>/dev/null || true
 
-          # Create new release with built cli.js
+          # Create new release with built cli.js and version file
           gh release create cli-latest \
             --title "CLI v${{ steps.version.outputs.version }}" \
             --notes "Pre-built CLI binary (auto-updated on every push to main).
 
           This release is used as a fallback by \`install.sh\` when the local build fails (e.g. Termux proot).
+          The \`version\` file is used by the CLI's auto-update check.
 
           **Version:** ${{ steps.version.outputs.version }}
           **Built:** $(date -u +%Y-%m-%dT%H:%M:%SZ)" \
             --prerelease \
-            packages/cli/cli.js
+            packages/cli/cli.js \
+            packages/cli/version
 
       - name: Upload cloud bundles
         env: