docs(01-02): complete model unit tests plan

- SUMMARY: 33 tests for HealthCheckModel (14) and AlertEventModel (19)
- STATE: Advanced to plan 02 complete, added 3 mock pattern decisions
- ROADMAP: Phase 1 Data Foundation marked complete (2/2 plans)

.planning/STATE.md

@@ -10,27 +10,27 @@ See: .planning/PROJECT.md (updated 2026-02-24)
 ## Current Position
 
 Phase: 1 of 4 (Data Foundation)
-Plan: 1 of TBD in current phase
+Plan: 2 of TBD in current phase
 Status: In progress
-Last activity: 2026-02-24 — Completed 01-01 (monitoring tables migration + model layer)
+Last activity: 2026-02-24 — Completed 01-02 (HealthCheckModel + AlertEventModel unit tests)
 
-Progress: [█░░░░░░░░░] 10%
+Progress: [██░░░░░░░░] 20%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 1
-- Average duration: ~8 min
-- Total execution time: ~0.13 hours
+- Total plans completed: 2
+- Average duration: ~17 min
+- Total execution time: ~0.57 hours
 
 **By Phase:**
 
 | Phase | Plans | Total | Avg/Plan |
 |-------|-------|-------|----------|
-| 01-data-foundation | 1 | ~8 min | ~8 min |
+| 01-data-foundation | 2 | ~34 min | ~17 min |
 
 **Recent Trend:**
-- Last 5 plans: 01-01 (8 min)
+- Last 5 plans: 01-01 (8 min), 01-02 (26 min)
 - Trend: —
 
 *Updated after each plan completion*
@@ -50,6 +50,9 @@ Recent decisions affecting current work:
 - 01-01: getSupabaseServiceClient() called per-method, never cached at module level
 - 01-01: checked_at column separate from created_at on service_health_checks (probe time vs DB write time)
 - 01-01: Forward-only migrations only (no rollback scripts)
+- 01-02: Supabase mock uses chain.then (thenability) so both .single() and direct await patterns work from one mock
+- 01-02: makeSupabaseChain() factory per test — no shared mock state between tests
+- 01-02: vi.mock() factories must use only inline vi.fn() to avoid Vitest hoisting TDZ errors
 
 ### Pending Todos
 
@@ -64,5 +67,5 @@ None yet.
 ## Session Continuity
 
 Last session: 2026-02-24
-Stopped at: Completed 01-01-PLAN.md — monitoring tables migration + HealthCheckModel + AlertEventModel
+Stopped at: Completed 01-02-PLAN.md — HealthCheckModel + AlertEventModel unit tests (33 tests passing)
 Resume file: None