chore: archive v1.2 Collection Power-Ups milestone

Archive roadmap and requirements to milestones/, evolve PROJECT.md
with validated requirements, update retrospective, and reorganize
ROADMAP.md with milestone groupings.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -2,10 +2,10 @@
 gsd_state_version: 1.0
 milestone: v1.2
 milestone_name: Collection Power-Ups
-status: completed
-stopped_at: Completed 09-02-PLAN.md
-last_updated: "2026-03-16T14:29:36.577Z"
-last_activity: 2026-03-16 -- Completed 09-02 weight breakdown visualization
+status: archived
+stopped_at: Milestone v1.2 archived
+last_updated: "2026-03-16T18:30:00.000Z"
+last_activity: 2026-03-16 -- Milestone v1.2 archived
 progress:
   total_phases: 3
   completed_phases: 3
@@ -21,16 +21,13 @@ progress:
 See: .planning/PROJECT.md (updated 2026-03-16)
 
 **Core value:** Make it effortless to manage gear and plan new purchases -- see how a potential buy affects your total setup weight and cost before committing.
-**Current focus:** Milestone v1.2 complete -- all phases finished
+**Current focus:** Planning next milestone
 
 ## Current Position
 
-Phase: 9 of 9 (Weight Classification & Visualization)
-Plan: 2 of 2
-Status: Complete
-Last activity: 2026-03-16 -- Completed 09-02 weight breakdown visualization
-
-Progress: [██████████] 100%
+Milestone v1.2 Collection Power-Ups archived.
+All 3 milestones shipped (v1.0, v1.1, v1.2).
+Next step: `/gsd:new-milestone` to start next milestone.
 
 ## Accumulated Context
 
@@ -38,23 +35,7 @@ Progress: [██████████] 100%
 
 (Full decision log in PROJECT.md Key Decisions table)
 
-- Coarse granularity: 19 requirements compressed into 3 phases (7-9)
-- Weight unit selection must be Phase 7 (formatWeight refactor touches all weight displays)
-- Classification belongs on setup_items join table, NOT items table
-- Candidate status and classification schema migrations in separate phases (sequential)
-- Weight conversion precision: g=0dp, oz=1dp, lb=2dp, kg=2dp
-- useWeightUnit validates stored value against known units to protect against corrupt data
-- Unit toggle placed between title and stats in TotalsBar for subtle utility placement
-- CategoryFilterDropdown kept separate from CategoryPicker (filter vs form concerns)
-- No debounce on search input (collection under 1000 items)
-- Individual clear controls for search and category filter (no combined clear-all)
-- [Phase 08]: CategoryFilterDropdown kept separate from CategoryPicker (filter vs form concerns)
-- [Phase 08]: StatusBadge popup uses click-outside + Escape dismiss pattern matching CategoryPicker
-- [Phase 08]: Status badge uses muted gray tones (bg-gray-100 text-gray-600) per user design decision
-- [Phase 09]: ClassificationBadge uses simple click-to-cycle (not popup) since only 3 values
-- [Phase 09]: Classification stored on setupItems join table so same item can differ across setups
-- [Phase 09]: syncSetupItems preserves classifications via Map before delete/restore after re-insert
-- [Phase 09]: Recharts v3 Cell component used for per-slice colors (still functional, deprecated for v4)
+Cleared at milestone boundary. v1.2 decisions archived in milestones/v1.2-ROADMAP.md.
 
 ### Pending Todos
 
@@ -66,6 +47,6 @@ None active.
 
 ## Session Continuity
 
-Last session: 2026-03-16T14:22:28.169Z
-Stopped at: Completed 09-02-PLAN.md
+Last session: 2026-03-16
+Stopped at: Milestone v1.2 archived
 Resume file: None