Document task-number allocation in Data layer (TaskEntity.Number,
next_task_number counter, invariants, insert paths).
Update Worker docs to clarify TaskIdResolver wiring (#123 → GUID lookup),
Number in MCP payloads, and correct the 'Two hard conventions' statement
(only the first is test-enforced).
Bump external-mcp.md verified-against commit to 38af549 (Slice 4 merge)
and add new sections on task ID resolution and numbering.
Add Slice 4 visual verification items to open.md (row/detail number display,
worker-log messages).
Verified against:
- src/ClaudeDo.Data/TaskNumberAllocator.cs
- src/ClaudeDo.Data/Repositories/TaskRepository.cs (AddAsync line 20, CreateChildAsync line 276)
- src/ClaudeDo.Worker/External/TaskIdResolver.cs
- src/ClaudeDo.Worker/External/ExternalMcpService.cs (TaskDto/TaskRefDto DTOs)
- tests/ClaudeDo.Worker.Tests/External/ExternalMcpToolSchemaTests.cs (only first convention test-enforced)