feat: RFC 0057 Phase 8-9 CLI parity implementation
Add CLI subcommands that call the same MCP handlers:
- `blue dialogue` - create, get, list, export dialogues
- `blue adr` - create, get, list, status ADRs
- `blue spike` - create, get, list, complete spikes
- `blue audit` - create, get, list audit docs
- `blue prd` - create, get, list PRDs
- `blue reminder` - create, list, snooze, dismiss reminders
Make blue-mcp handlers module public for CLI access.
Phases 8-9 complete; Phase 10 (staging, llm, etc.) deferred.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>