docs: freeze YuXinGu lexicon, journey, and P1 engineering sources

Establish product language contract, user journey with dual growth engines,
ERD/OpenAPI/Go boundaries, and H5 routes (/profile, /portrait, /relation,
/membership) before P1 implementation.

Co-authored-by: Cursor <cursoragent@cursor.com>

.ai/playbooks/new-page.md

@@ -5,14 +5,15 @@ Use when: “新增页面”
 ## Steps
 
 1. Confirm IA tab vs secondary page (`.ai/ui.md`)
-2. Read `.ai/design/design-system.md` + `component-catalog.md` + `design/platform/h5.md`
-3. Reuse catalog components; update catalog if adding a new one
-4. Add route in `apps/user-h5/src/router`
-5. Add `pages/XxxPage.vue` (PascalCase); tokens only (no raw brand hex)
-6. Extract components if file approaches 300–400 lines
-7. Data via `src/api` → `@yuxingu/sdk` only
-8. Use domain words from `.ai/domain.md`
-9. Loading / empty / error states
-10. Compliance copy if report-like
-11. `npm run build:h5`
-12. Review + checklist/feature.md
+2. Read `.ai/product/lexicon.md` + `feature-map.md`（文案禁用词）
+3. Read `.ai/design/design-system.md` + `component-catalog.md` + `design/platform/h5.md`
+4. Reuse catalog components; update catalog if adding a new one
+5. Add route in `apps/user-h5/src/router`
+6. Add `pages/XxxPage.vue` (PascalCase); tokens only (no raw brand hex)
+7. Extract components if file approaches 300–400 lines
+8. Data via `src/api` → `@yuxingu/sdk` only
+9. Domain terms from `.ai/domain.md`；UI 中文从 lexicon
+10. Loading / empty / error states
+11. Compliance copy if 成长报告-like
+12. `npm run build:h5`
+13. Review + checklist/feature.md