Replace 5 separate tool registrars (messaging, channels, swarm,
attachments, webhooks) with a single HybridToolRegistrar exposing
4 tools: my_status, send_message, search, and execute.
New foundation packages:
- internal/actions: action registry (22 actions) + BM25 search index
- internal/jsruntime: lightweight call() expression parser with
concurrency-limited execution pool
The `execute` tool dispatches call() expressions through a
ServiceBridge that maps action names to existing service methods,
preserving all original handler logic. The `search` tool enables
agents to discover available actions by keyword. The `send_message`
tool merges DM and channel sending with mutual exclusion.
All unit tests, integration tests, build, and vet pass.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>