feat: browser access (allowed_origins, CORS with Private Network Access), job cancel, Tomie/Unity adapters, benchmark

Includes earlier uncommitted work: Tomie and Unity adapters, benchmark, structured output, call metrics.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitignore

@@ -5,3 +5,5 @@ __pycache__/
 data/
 config.toml
 .env
+benchmark.json
+tomie.json