docs: update README — Phase 3 in progress, plan 1/6 complete

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

README.md

@@ -266,17 +266,27 @@ Instead of a standard circular ring (Instagram-style), active stories are indica
 - **Milestones:** 5 structured milestone types (Birthday, Adoption Day, First Outing, Vet Visit, New Litter), distinct orange card, PostTypeSheet fully wired for all 3 post types
 - **Profile:** Posts 3-col grid + Milestones tab
 
-### Phase 3 — Engagement (planned)
+### Phase 3 — Engagement and Discovery (in progress — plan 1/6 done)
 
-Likes, comments, reactions, notifications, explore/search.
+Schema foundation complete (2026-06-13):
+- **DB schema:** `Reaction`, `Comment`, `Repost`, `Hashtag`, `PostHashtag` models; `PostType.REPOST` enum
+- **tRPC stubs:** `reactions`, `comments`, `reposts`, `explore`, `search` routers registered
+- **Test scaffolds:** 5 files, 14 failing RED tests covering ENGM-01–04, EXPL-01, SRCH-01–02
 
-### Phase 4 — Growth (planned)
+Remaining plans:
+- **03-02:** Paw reactions (single 🐾 per post, toggle on/off, count on PostCard)
+- **03-03:** Flat comments (create/delete own, CommentSheet drawer)
+- **03-04:** Paw-Back / repost with attribution header (PostType.REPOST in feed)
+- **03-05:** Explore page (species tabs + breed filter) + pet name/breed search
+- **03-06:** Hashtag extraction on post create, hashtag search, clickable `#tags` in captions
 
-Follower-milestone auto-trigger, push notifications, pet discovery.
+### Phase 4 — Notifications (planned)
+
+In-app notification center: follows, paw reactions, comments, DMs.
 
 ### Phase 5 — Video (planned)
 
-Short-form video stories and posts via Mux (HLS adaptive streaming).
+Short-form video posts via Mux (signed upload → HLS adaptive streaming).
 
 ### Phase 6 — Messaging (planned)
 
@@ -284,7 +294,7 @@ Direct messages between pet owners via Supabase Realtime.
 
 ### Phase 7 — Health (planned)
 
-Vet records, vaccination logs, weight tracking.
+Vet records, vaccination logs, weight tracking, shareable health card.
 
 ---
 
@@ -293,11 +303,13 @@ Vet records, vaccination logs, weight tracking.
 Tests are unit tests only (no DB, no network). Prisma and Redis are mocked per file using `createMockPrisma()` from `src/__tests__/helpers/prisma-mock.ts`.
 
 ```bash
-npx vitest run          # full suite (~3-4s)
+npx vitest run          # full suite (~4s)
 npx vitest              # watch mode
 ```
 
-> `src/__tests__/media-upload.test.ts` currently fails due to a missing Supabase URL in the test environment. This is a pre-existing issue from Phase 1 and does not affect any Phase 2 tests.
+**Current state:** 53 passing (Phase 1+2), 14 failing RED (Phase 3 — NOT_IMPLEMENTED stubs, intentional), 1 pre-existing failure.
+
+> `src/__tests__/media-upload.test.ts` currently fails due to a missing Supabase URL in the test environment. This is a pre-existing issue from Phase 1 and does not affect Phase 2 or Phase 3 tests.
 
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