docs(16-02): complete service layer userId scoping plan

- SUMMARY.md documents 7 service files updated with userId parameter
- STATE.md advanced to plan 2 of 4 in phase 16
- ROADMAP.md updated with plan progress
- Requirements MULTI-01, MULTI-02, MULTI-03, MULTI-06 marked complete

.planning/STATE.md

@@ -1,16 +1,16 @@
 ---
 gsd_state_version: 1.0
-milestone: v2.0
-milestone_name: Platform Foundation
+milestone: v1.3
+milestone_name: Research & Decision Tools
 status: executing
-stopped_at: null
-last_updated: "2026-04-05"
-last_activity: 2026-04-05 — Completed 16-01-PLAN.md (multi-user data model foundation)
+stopped_at: Completed 16-02-PLAN.md
+last_updated: "2026-04-05T08:45:22.411Z"
+last_activity: 2026-04-05
 progress:
-  total_phases: 5
-  completed_phases: 0
-  total_plans: 4
-  completed_plans: 1
+  total_phases: 10
+  completed_phases: 8
+  total_plans: 25
+  completed_plans: 21
   percent: 5
 ---
 
@@ -26,15 +26,16 @@ See: .planning/PROJECT.md (updated 2026-04-03)
 ## Current Position
 
 Phase: 16 of 18 (Multi-User Data Model)
-Plan: 1 of 4 in current phase
-Status: Plan 16-01 complete, executing remaining plans
-Last activity: 2026-04-05 — Completed 16-01 (multi-user data model foundation)
+Plan: 2 of 4 in current phase
+Status: Ready to execute
+Last activity: 2026-04-05
 
 Progress: [#---------] 5% (v2.0 milestone)
 
 ## Performance Metrics
 
 **Velocity:**
+
 - Total plans completed: 1 (v2.0 milestone)
 - Average duration: 8min
 - Total execution time: 8min
@@ -46,6 +47,7 @@ Progress: [#---------] 5% (v2.0 milestone)
 ### Decisions
 
 Key decisions made during v2.0 execution:
+
 - Platform pivot: single-user to multi-user with discovery-first approach
 - External auth provider (self-hosted, open-source) — Logto vs Authentik OPEN decision
 - SQLite to Postgres migration — required by auth provider and multi-user concurrency
@@ -55,6 +57,9 @@ Key decisions made during v2.0 execution:
 - All API routes require auth (no GET bypass) for per-user data scoping (16-01)
 - OAuth service converted from sync to async for pg compatibility (16-01)
 - getOrCreateUncategorized placed in category.service.ts (16-01)
+- [Phase 16]: Category deletion uses dynamic getOrCreateUncategorized per user instead of hardcoded ID
+- [Phase 16]: Candidate operations verify parent thread ownership for cross-user isolation
+- [Phase 16]: syncSetupItems validates both setup and item ownership via inArray
 
 ### Pending Todos
 
@@ -67,6 +72,6 @@ None active.
 
 ## Session Continuity
 
-Last session: 2026-04-05
-Stopped at: Completed 16-01-PLAN.md (multi-user data model foundation)
+Last session: 2026-04-05T08:45:22.408Z
+Stopped at: Completed 16-02-PLAN.md
 Resume file: None