Add project taskitem pool and planner fixes

docs/AGENT_HANDOFF_2026-03-18_taskitem_pool.md

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+# Agent Handoff 2026-03-18
+
+## Summary
+
+This handoff covers two related pieces of work:
+
+1. The Whetstone planning pipeline for `whimpwm` was debugged and improved so the `sprint_001_execution_spec_whetstone.md` run now produces a usable queue.
+2. A project-scoped taskitem pool was added so external agents can claim/release/complete generated taskitems directly from the target project without relying on an always-running orchestrator.
+
+## Key Outcomes
+
+- Fixed the spec-to-taskitem path so prose sections are preserved and mapped into better normalized requirements.
+- Fixed workspace-aware target inference so generated taskitems no longer drift into Whetstone internals when planning for another project.
+- Added a project-side taskitem pool persisted under `.whetstone/<project>.taskitem_pool.json`.
+- Added MCP tools:
+  - `whetstone_import_taskitem_pool`
+  - `whetstone_list_taskitem_pool`
+  - `whetstone_claim_taskitem`
+  - `whetstone_release_taskitem`
+  - `whetstone_complete_pooled_taskitem`
+- Added lock-based contention safety for the pool using a `.lock` sidecar plus atomic temp-file writes.
+- Fixed MCP error shaping so failed claims now surface as proper tool errors with `isError: true`.
+
+## Files Changed
+
+- `editor/src/ArchitectIntakeProcessor.h`
+- `editor/src/RequirementsParser.h`
+- `editor/src/ScopeMilestoneDecomposer.h`
+- `editor/src/SelfContainmentScorer.h`
+- `editor/src/mcp/RegisterArchitectIntakeTools.h`
+- `editor/src/mcp/RegisterValidationTools.h`
+- `tools/mcp/run_sprint_taskitem_pipeline.sh`
+- `editor/src/TaskitemPoolPersistence.h`
+- `editor/src/mcp/RegisterTaskitemPoolTools.h`
+- `editor/src/AgentPermissionPolicy.h`
+- `editor/src/HeadlessAgentRPCHandler.h`
+- `editor/src/headless_rpc/DispatchPart5.h`
+- `editor/src/MCPServer.h`
+- `editor/src/mcp/RegisterOnboardingAndAllTools.h`
+
+## Verified Behavior
+
+- `whetstone_mcp` rebuild succeeds.
+- `whimpwm` queue import succeeds from:
+  - `logs/taskitem_runs/sprint_001_execution_spec_whetstone_20260317_214642/02_generate_taskitems.json`
+- Project pool persists at:
+  - `/home/bill/Documents/whimpwm/.whetstone/whimpwm.taskitem_pool.json`
+- Concurrency test succeeded:
+  - two workers racing to claim the same task resulted in exactly one claim winner
+  - loser returned `Taskitem not ready` with `isError: true`
+
+## Current `whimpwm` State
+
+- The `whimpwm` pool was reset to a clean imported state before handoff.
+- Current counts:
+  - `ready: 6`
+  - `blocked: 1`
+  - `total: 7`
+- No task is currently claimed.
+
+## Recommended Next Steps
+
+1. Add a lightweight MCP/import bridge from planner runs into workflow items if you still want parity between the legacy workflow system and the project-scoped pool.
+2. Decide whether `.whetstone/*.taskitem_pool.json` should remain runtime-only or become a versioned artifact for some projects.
+3. Add explicit tests for:
+   - import/claim/release/complete lifecycle
+   - concurrent claim contention
+   - error-shaping contract on failed pool mutations
+4. Start real worker execution against the `whimpwm` queue now that the pool path is usable.