docs: update retrospective for v1.0

.planning/RETROSPECTIVE.md

@@ -0,0 +1,67 @@
+# Project Retrospective
+
+*A living document updated after each milestone. Lessons feed forward into future planning.*
+
+## Milestone: v1.0 — MVP
+
+**Shipped:** 2026-03-15
+**Phases:** 3 | **Plans:** 10 | **Commits:** 53
+
+### What Was Built
+- Full gear collection with item CRUD, categories, weight/cost totals, and image uploads
+- Planning threads with candidate comparison and thread resolution into collection
+- Named setups (loadouts) composed from collection items with live totals
+- Dashboard home page with summary cards
+- Onboarding wizard for first-time user experience
+- Service-level and route-level integration tests
+
+### What Worked
+- Coarse 3-phase structure kept momentum high — no planning overhead between tiny phases
+- TDD approach for backend (service tests first) caught issues early and made frontend integration smooth
+- Service layer with DI (db as first param) made testing trivial with in-memory SQLite
+- Visual verification checkpoints at end of each phase caught UI issues before moving on
+- Bun + Vite + Hono stack had zero friction — everything worked together cleanly
+
+### What Was Inefficient
+- Verification plans (XX-03) were mostly rubber-stamp auto-approvals in yolo mode — could skip for v2
+- Some ROADMAP plan checkboxes never got checked off (cosmetic, didn't affect tracking)
+- Performance metrics in STATE.md had stale placeholder data alongside real data
+
+### Patterns Established
+- Service functions: `(db, params) => result` with production db default
+- Route-level integration tests using Hono context variables for db injection
+- Prices in cents everywhere, display conversion in UI only
+- Tab navigation via URL search params for shareability
+- Atomic sync pattern: delete-all + re-insert in transaction
+
+### Key Lessons
+1. Coarse granularity (3 phases for an MVP) is the right call for a greenfield app — avoids over-planning
+2. The Vite proxy pattern is required when using TanStack Router plugin — can't do Bun fullstack serving
+3. drizzle-kit needs better-sqlite3 even on Bun — can't use bun:sqlite for migrations
+4. Onboarding state belongs in the database (settings table), not in client-side stores
+
+### Cost Observations
+- Model mix: quality profile throughout
+- Sessions: ~10 plan executions across 2 days
+- Notable: Most plans completed in 3-5 minutes, total wall time under 1 hour
+
+---
+
+## Cross-Milestone Trends
+
+### Process Evolution
+
+| Milestone | Commits | Phases | Key Change |
+|-----------|---------|--------|------------|
+| v1.0 | 53 | 3 | Initial build, coarse granularity, TDD backend |
+
+### Cumulative Quality
+
+| Milestone | LOC | Files | Tests |
+|-----------|-----|-------|-------|
+| v1.0 | 5,742 | 114 | Service + route integration |
+
+### Top Lessons (Verified Across Milestones)
+
+1. Coarse phases with TDD backend → smooth frontend integration
+2. Service DI pattern enables fast, reliable testing without mocks