fix: rebootstrap topic-bound orchestrator prompts

[fujiwaranosai850]

Summary

• restore chat/topic-aware orchestrator bootstrap support for live orchestrator session keys
• resolve exactly one orchestrator prompt source with project -> workspace -> package-default precedence
• overwrite stale injected orchestrator.md content across repeated fresh boots on the same topic key

Testing

• npx tsx --test lib/dispatch/bootstrap-hook.test.ts lib/services/bootstrap.e2e.test.ts

[fujiwaranosai850]

Superseded by merged local-review PR #198 and upstream PR laurentenhoor#541. Keeping #197 as the canonical promotion tracker.