docs(02-03): complete asset generation and DB accessors plan

- SUMMARY: 6 IndexedDB accessors + 9 generated assets via Gemini API
- STATE: advance to plan 4/5, 90% progress
- ROADMAP: update phase 02 plan progress
- REQUIREMENTS: mark ASST-01, ASST-02 complete

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 status: executing
-stopped_at: Completed 02-04-PLAN.md
-last_updated: "2026-03-29T10:06:43.421Z"
+stopped_at: Completed 02-03-PLAN.md
+last_updated: "2026-03-29T10:12:19.423Z"
 last_activity: 2026-03-29
 progress:
   total_phases: 4
   completed_phases: 1
   total_plans: 10
-  completed_plans: 8
+  completed_plans: 9
   percent: 0
 ---
 
@@ -26,7 +26,7 @@ See: .planning/PROJECT.md (updated 2026-03-29)
 ## Current Position
 
 Phase: 02 (gemini-integration-asset-pipeline) — EXECUTING
-Plan: 4 of 5
+Plan: 5 of 5
 Status: Ready to execute
 Last activity: 2026-03-29
 
@@ -60,6 +60,7 @@ Progress: [░░░░░░░░░░] 0%
 | Phase 02 P02 | 2min | 2 tasks | 8 files |
 | Phase 02 P01 | 3min | 1 tasks | 6 files |
 | Phase 02 P04 | 1min | 1 tasks | 2 files |
+| Phase 02 P03 | 6min | 2 tasks | 12 files |
 
 ## Accumulated Context
 
@@ -83,6 +84,8 @@ Recent decisions affecting current work:
 - [Phase 02]: Image generation no retry (expensive), text retries 3x exponential backoff
 - [Phase 02]: Config loader caches after first fetch, resetConfigCache() for testing
 - [Phase 02]: Each companion function independently checks config and rate limits (no shared wrapper) for clarity
+- [Phase 02]: Fixed imageModel name: gemini-3.1-flash-preview-image -> gemini-3.1-flash-image-preview (was 404)
+- [Phase 02]: Asset generation script skips existing files for idempotent re-runs
 
 ### Pending Todos
 
@@ -94,6 +97,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-03-29T10:06:43.414Z
-Stopped at: Completed 02-04-PLAN.md
+Last session: 2026-03-29T10:12:19.416Z
+Stopped at: Completed 02-03-PLAN.md
 Resume file: None