docs(19): create phase plan

.planning/ROADMAP.md

@@ -6,7 +6,7 @@
 - ✅ **v1.1 Fixes & Polish** — Phases 4-6 (shipped 2026-03-15)
 - ✅ **v1.2 Collection Power-Ups** — Phases 7-9 (shipped 2026-03-16)
 - 🚧 **v1.3 Research & Decision Tools** — Phases 10-13 (in progress)
-- 📋 **v2.0 Platform Foundation** — Phases 14-18 (planned)
+- 📋 **v2.0 Platform Foundation** <EFBFBD><EFBFBD> Phases 14-22 (planned)
 
 ## Phases
 
@@ -55,6 +55,10 @@
 - [ ] **Phase 16: Multi-User Data Model** — Add user ownership to all entities with cross-user data isolation
 - [ ] **Phase 17: Object Storage** — Move images from local filesystem to MinIO (S3-compatible)
 - [x] **Phase 18: Global Items & Public Profiles** — Global item catalog, user profiles, and public setup sharing (completed 2026-04-05)
+- [ ] **Phase 19: Reference Item Model & Tags Schema** — Collection items as references to global catalog, tag system for discovery
+- [ ] **Phase 20: FAB & Full-Screen Catalog Search** — Global FAB with mini menu, full-screen catalog search with tag filtering
+- [ ] **Phase 21: Add-from-Catalog & Thread Integration** — Add catalog items to collection and threads, resolution creates reference items
+- [ ] **Phase 22: Manual Entry Fallback** — Manual add for items not in catalog, non-functional submission prompt
 
 ## Phase Details
 
@@ -171,6 +175,56 @@ Plans:
 **Plans**: TBD
 **UI hint**: yes
 
+### Phase 19: Reference Item Model & Tags Schema
+**Goal**: Collection items can be references to global catalog entries, and global items support tags for discovery
+**Depends on**: Phase 18
+**Requirements**: CATFLOW-03, CATFLOW-04, CATFLOW-05, CATFLOW-06, TAG-01, TAG-02
+**Success Criteria** (what must be TRUE):
+  1. A collection item can reference a global item and displays merged data (global base + personal fields)
+  2. Global items can have multiple tags, searchable via API
+  3. Thread candidates can link to a global item via globalItemId
+  4. Resolving a thread with a catalog-linked candidate creates a reference item with auto-link
+**Plans:** 3 plans
+Plans:
+- [ ] 19-01-PLAN.md — Schema, migration, Zod schemas, types, seed script
+- [ ] 19-02-PLAN.md — Item service COALESCE merge, thread resolution, route cleanup
+- [ ] 19-03-PLAN.md — Global item tag filtering, secondary service merge propagation
+
+### Phase 20: FAB & Full-Screen Catalog Search
+**Goal**: Users discover and add gear through a catalog-first search experience with tag filtering
+**Depends on**: Phase 19
+**Requirements**: CATFLOW-01, CATFLOW-02
+**Success Criteria** (what must be TRUE):
+  1. FAB visible on all pages with mini menu showing "Add to Collection" and "Start Thread"
+  2. "New Setup" option appears in FAB on setups page only
+  3. Full-screen catalog search overlay opens from either add option
+  4. Search results display catalog items with name, weight, price, owner count
+  5. Tag chips filter search results
+**Plans**: TBD
+**UI hint**: yes
+
+### Phase 21: Add-from-Catalog & Thread Integration
+**Goal**: Users can add catalog items to their collection and to threads directly from search
+**Depends on**: Phase 20
+**Requirements**: CATFLOW-03, CATFLOW-05, CATFLOW-06
+**Success Criteria** (what must be TRUE):
+  1. User can add a catalog item to collection with one confirmation step (category picker + notes)
+  2. User can add catalog items as thread candidates instantly from search
+  3. Resolving a catalog-linked candidate creates a properly linked reference item in collection
+**Plans**: TBD
+**UI hint**: yes
+
+### Phase 22: Manual Entry Fallback
+**Goal**: Users can still add items not found in the catalog via manual entry
+**Depends on**: Phase 21
+**Requirements**: CATFLOW-07, CATFLOW-08
+**Success Criteria** (what must be TRUE):
+  1. User can fall back to manual entry from catalog search via "Add Manually" link
+  2. Manual entry saves a standalone collection item (no globalItemId)
+  3. "Submit to catalog?" prompt appears after manual save but takes no backend action
+**Plans**: TBD
+**UI hint**: yes
+
 ## Progress
 
 | Phase | Milestone | Plans Complete | Status | Completed |
@@ -193,3 +247,7 @@ Plans:
 | 16. Multi-User Data Model | v2.0 | 0/? | Not started | - |
 | 17. Object Storage | v2.0 | 0/? | Not started | - |
 | 18. Global Items & Public Profiles | v2.0 | 4/5 | Complete    | 2026-04-05 |
+| 19. Reference Item Model & Tags Schema | v2.0 | 0/3 | Not started | - |
+| 20. FAB & Full-Screen Catalog Search | v2.0 | 0/? | Not started | - |
+| 21. Add-from-Catalog & Thread Integration | v2.0 | 0/? | Not started | - |
+| 22. Manual Entry Fallback | v2.0 | 0/? | Not started | - |