fix: streamline CI/CD — remove broken AI docs updater, fix Docker publish

- Delete ai-docs-updater.yml (never worked: missing ANTHROPIC_API_KEY, tsx not found)
- Delete standalone docker-publish.yml (GITHUB_TOKEN can't trigger cross-workflow)
- Merge Docker build/push into release.yml as dependent job using .release-version
- Add publishCmd to .releaserc.json to signal new releases to Docker job
- Fix deploy-docs.yml: upgrade pnpm@v3→v4, node 20→22, add --frozen-lockfile
- Fix ci.yml: rename job to "Typecheck" (no lint step existed)

.releaserc.json

@@ -18,7 +18,8 @@
     [
       "@semantic-release/exec",
       {
-        "prepareCmd": "./scripts/sync-version.sh ${nextRelease.version}"
+        "prepareCmd": "./scripts/sync-version.sh ${nextRelease.version}",
+        "publishCmd": "echo '${nextRelease.version}' > .release-version"
       }
     ],
     [