docs: settle open design items + dogfood backlog

Resolve the five design-session open items from PLAN.md:
- decisions.md: soft write-path, poll-only sync (NAT), lognormal
  cold-start priors, purity test binds the SQLite cache
- pm-state.md: sidecar layout + directive/capacity/calibration
  schemas + lifecycle inference table
- agent-tools.md: query_project read tool + three write tools

Also gitignore .env.* (protect the gitea PAT) and record the P0
actual: 10 labels, 5 milestones, 34 tracer-bullet issues + 51
dependencies filed on christian/commitea as the first managed project.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/PLAN.md

@@ -87,7 +87,11 @@ directives. Electron app, one window, "tell me what to do" experience.
 Deliverables per phase; replace TBD with actuals at phase close.
 
 - **P0 — Scaffold** — repo, Electron shell, gitea API client + token auth,
-  `pm-state` repo bootstrap. Actual: TBD
+  `pm-state` repo bootstrap. Actual (2026-07-08): yarn4 workspaces + electron
+  shell + `@commitea/core` label schema + design system mirrored. **Dogfood
+  backlog filed** on `christian/commitea`: 10 labels (est/p/deadline, exclusive
+  scopes), 5 phase milestones, 34 tracer-bullet issues with 51 native
+  dependencies. `pm-state` repo bootstrap still pending (P1-6 / P5-1).
 - **P1 — Sync + data model** — read mirror into SQLite cache, webhook
   listener + reconcile-on-launch, lifecycle inference from event stream,
   label schema applied. Actual: TBD
@@ -113,12 +117,16 @@ vertical slices within phases where possible.)
 - Concurrent multi-PM directive writing
 - Cloud LLM as *requirement* (it's a config option, not a dependency)
 
-## Open items for design session
+## Open items for design session — RESOLVED 2026-07-08
 
-- Chat-as-only-write-path: strict or soft (UI edits allowed but agent
-  observes/objects)?
-- `pm-state` file formats (JSONL event log settled; capacity/calibration
-  schemas TBD)
-- Tool schema for the fat `query_project` tool
-- Webhook endpoint mechanics per instance (port allocation, cleanup on quit)
-- Cold-start estimate distributions (industry priors vs uniform pessimism)
+Settled in [decisions.md](./decisions.md), [pm-state.md](./pm-state.md),
+[agent-tools.md](./agent-tools.md):
+
+- Chat-as-only-write-path → **soft, split by semantics** (decisions.md D1)
+- `pm-state` file formats → directive/capacity/calibration schemas (pm-state.md)
+- Fat `query_project` tool schema → one read tool + three write tools
+  (agent-tools.md)
+- Webhook mechanics → **poll + reconcile only in v1** (NAT), behind a
+  `ChangeSource` interface (decisions.md D2)
+- Cold-start distributions → **lognormal per-bucket priors** in code
+  (decisions.md D3)