CC 2.1.117 adoption + Milestone #117 Tier A

Plan vs. reality. Only 2 of 4 issues needed work — the other 2 were based on a misread of the matrix.

What shipped

Issue	Planned effort	Actual effort	Outcome
#1441 CC 2.1.117 adoption	60 min	40 min	14 matrix entries, MIN bump, doc table, mcpServers audit
#1440 CHANGELOG ghost	5 min	2 min	Ghost removed
#1444 hook backfill (4 events)	90 min	0 min	Invalid premise — all 4 already registered
#1445 deprecated-ref sweep	20 min	0 min	Invalid premise — no actual drift

2.1.117 matrix additions (14)

agent_mcp_servers_main_thread — parallels 2.1.116's agent_hooks_main_thread
fork_subagent_env_var (CLAUDE_CODE_FORK_SUBAGENT=1)
plugin_install_auto_deps / marketplace_install_auto_deps
managed_settings_marketplace_enforce
model_pin_persists_restart + resume_large_session_summary
otel_command_attrs + otel_effort_attr
opus_46_sonnet_46_default_high — real cost change for Pro/Max
advisor_tool_experimental + retention_expands_tasks_backups
native_bfs_ugrep + opus_47_context_window_fix

The 3 "already done" issues closed

#1444, #1449, #1453 were all filed based on the brainstorm's misread of cc-version-matrix.ts: having a matrix entry means the feature is TRACKED in compatibility, not that there's no hook. All 27 hook events actually have at least one registered handler.

Honest session note

Tier A was scoped at ~2-3 hours; real work took ~45 min because 2 of 4 issues evaporated on verification. This is exactly the kind of error the brainstorm should have caught by grep'ing hooks.json before filing. Lesson for /ork:brainstorm: verify claims against current code state, not against mental model.

Test plan

cd src/hooks && npx vitest run         7766/7766 pass
npm run build                          ✓
npm run test:skills + test:agents      ✓
./bin/validate-counts.sh               PASSED

Remaining in milestone #117

Tier B (#1446 MCP audit, #1447 Monitor wiring, #1448 OTEL analytics) + Tier C (#1450 PushNotification, #1451 release cadence, #1452 property-based testing) still open as originally scoped. Test-infra follow-ups #1436 and #1438 also still open.