chore: complete v1.1 milestone — Fixes & Polish

Archive v1.1 artifacts (roadmap, requirements, phases) to milestones/.
Evolve PROJECT.md with shipped requirements and new key decisions.
Reorganize ROADMAP.md with collapsed milestone groupings.
Update retrospective with v1.1 lessons.

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

.planning/RETROSPECTIVE.md

@@ -47,6 +47,50 @@
 
 ---
 
+## Milestone: v1.1 — Fixes & Polish
+
+**Shipped:** 2026-03-15
+**Phases:** 3 | **Plans:** 7 | **Files changed:** 65
+
+### What Was Built
+- Fixed threads table and thread creation with categoryId support and modal dialog
+- Overhauled planning tab with educational empty state, pill tabs, and category filter
+- Fixed image display bug (Zod schema missing imageFilename)
+- Redesigned image upload as 4:3 hero preview area with placeholders on all cards
+- Migrated categories from emoji to Lucide icons with 119-icon curated picker
+- Built IconPicker with search, 8 group tabs, and portal popover
+
+### What Worked
+- Auto-advance pipeline (discuss → plan → execute) completed both phases end-to-end without manual intervention
+- Wave-based parallel execution in Phase 6 — plans 06-02 and 06-03 ran concurrently with no conflicts
+- Executor auto-fix deviations handled cascading renames gracefully (emoji→icon required touching hooks/routes beyond plan scope)
+- Context discussion upfront captured clear decisions — no ambiguity during execution
+- Verifier caught real issues (Zod schema root cause) and confirmed all must-haves
+
+### What Was Inefficient
+- Schema renames cascade through many files (12 in 06-01) — executors had to auto-fix downstream references not in the plan
+- Some ROADMAP.md plan checkboxes remained unchecked despite plans completing (cosmetic tracking drift)
+- Phase 5 executor installed inline SVGs for ImageUpload icons, then Phase 6 added lucide-react anyway — could have coordinated
+
+### Patterns Established
+- Portal-based popover pattern: reused from EmojiPicker → IconPicker (click-outside, escape, portal rendering)
+- LucideIcon dynamic lookup component: `icons[name]` from lucide-react for runtime icon resolution
+- Curated icon data file pattern: static data organized by groups for picker UIs
+- Hero image area: full-width 4:3 preview at top of forms with placeholder/upload/preview states
+
+### Key Lessons
+1. Zod validation middleware silently strips unknown fields — always add new schema fields to Zod schemas, not just DB schema
+2. Auto-fix deviations are a feature, not a bug — executors that fix cascading renames save manual replanning
+3. Auto-advance pipeline works well for straightforward phases — interactive discussion ensures decisions are clear before autonomous execution
+4. Parallel Wave 2 execution with no file overlap is safe and efficient
+
+### Cost Observations
+- Model mix: opus for execution, sonnet for verification/checking
+- Sessions: 1 continuous auto-advance pipeline for both phases
+- Notable: Full milestone (discuss + plan + execute × 2 phases) completed in a single session
+
+---
+
 ## Cross-Milestone Trends
 
 ### Process Evolution
@@ -54,14 +98,18 @@
 | Milestone | Commits | Phases | Key Change |
 |-----------|---------|--------|------------|
 | v1.0 | 53 | 3 | Initial build, coarse granularity, TDD backend |
+| v1.1 | ~30 | 3 | Auto-advance pipeline, parallel wave execution, auto-fix deviations |
 
 ### Cumulative Quality
 
 | Milestone | LOC | Files | Tests |
 |-----------|-----|-------|-------|
 | v1.0 | 5,742 | 114 | Service + route integration |
+| v1.1 | 6,134 | ~130 | Service + route integration (updated for icon schema) |
 
 ### Top Lessons (Verified Across Milestones)
 
 1. Coarse phases with TDD backend → smooth frontend integration
 2. Service DI pattern enables fast, reliable testing without mocks
+3. Always update Zod schemas alongside DB schema — middleware silently strips unvalidated fields
+4. Auto-advance pipeline (discuss → plan → execute) works well for clear-scope phases