docs(m3): expand Create SoT for submission-ready exit

Reorganize docs for humans: README map (goals / shipped / M3), PRODUCT
overview, and a specific CREATE.md that pulls Woo sync, metadata, pricing,
and inference requirements from main. Exit criteria is a slab submission-
ready for WooCommerce, proven with a SLAB-UAT-* draft. Add UAT-PRACTICE.

README.md

@@ -2,12 +2,17 @@
 
 Lists one-of-a-kind wood slabs on Whidbey Wood Store.
 
+Start at [`docs/README.md`](docs/README.md) for goals, what already shipped, and Milestone 3.
+
 | Artifact | File |
 |---|---|
-| PRD | `docs/PRODUCT.md` |
+| Docs map | `docs/README.md` |
+| Product overview | `docs/PRODUCT.md` |
 | Invariants and agent context | `AGENTS.md` |
-| Milestone 1 | `docs/CAPTURE.md` |
-| Milestone 2 | `docs/PHOTOS.md` |
+| Milestone 1 Capture (shipped) | `docs/CAPTURE.md` |
+| Milestone 2 Photos (shipped) | `docs/PHOTOS.md` |
+| Milestone 3 Create (current) | `docs/CREATE.md` |
+| UAT practice walk | `docs/UAT-PRACTICE.md` |
 | Hosting | `deploy/` |
 
 Owner: Ty. Store: https://www.whidbeywoodstore.com/