refactor(packages): extract boulder-state package

.omo/evidence/task-9-loc-check.txt

@@ -0,0 +1,12 @@
+169 packages/boulder-state/src/storage/write-state.ts
+147 packages/boulder-state/src/storage/task.ts
+141 packages/boulder-state/src/storage/read-state.ts
+88 packages/boulder-state/src/storage/plan-progress.ts
+79 packages/boulder-state/src/storage/session.ts
+74 packages/boulder-state/src/storage/shared.ts
+73 packages/boulder-state/src/types.ts
+57 packages/boulder-state/src/top-level-task.ts
+42 packages/boulder-state/src/index.ts
+34 packages/boulder-state/src/storage/path.ts
+15 packages/boulder-state/src/storage/index.ts
+6 packages/boulder-state/src/constants.ts

.omo/evidence/task-9-no-coupling.txt

@@ -0,0 +1,3 @@
+grep pattern: OpenCode
+scope: packages/boulder-state/src/**/*.ts
+result: no matches

.omo/notepads/package-layering-refactor/decisions.md

@@ -8,3 +8,12 @@ Net effect: utils package ships 12 files instead of 13.
 Choice: Option A
 Reason: Small call-site surface; keeps full jsonc-parser API together in the new package and avoids split ownership.
 Call sites changed: src/plugin-config.ts, src/cli/config-manager/config-context.ts, src/cli/doctor/checks/config.ts, src/cli/doctor/checks/model-resolution-config.ts, src/cli/doctor/checks/team-mode.ts, src/cli/doctor/checks/tools-lsp.ts, src/shared/project-discovery-dirs.ts, packages/utils/src/jsonc-parser.test.ts, packages/utils/src/jsonc-parser.memoization.test.ts
+
+## [2026-05-21T02:05:00Z] Task 9 (worktree)
+storage.ts split plan (from 977 LOC monolith):
+- `storage/shared.ts`: constants, timestamp/parsing helpers, mirror<->work projection, state normalization.
+- `storage/read.ts`: path resolution, file read/parse, plan discovery/progress parsing, read-only selectors.
+- `storage/write.ts`: persist/clear, create state/work IDs, active work selection, work lifecycle updates.
+- `storage/session.ts`: session-id tracking append logic (global + per-work).
+- `storage/task.ts`: task-session CRUD and timer transitions.
+- `storage/index.ts`: public API barrel with explicit named exports (no wildcard export).