Add public account-deletion page for Google Play (#103) (#110)

## Summary
- Closes [#103](#103).
- Adds public SPA route `/account-deletion/` (no auth) with Hesychia / `ai.hesychia.chat` branding, in-app deletion steps, soft-delete data retention copy, and a contact path (30-day SLA) for users who cannot sign in.
- Documents Play Console **Account deletion URL** in `ANDROID.md` and `android/README.md` (`https://hesychia.ai/account-deletion/`, legacy host, HashRouter form).

## Notes
- Retention copy matches backend soft-delete (v1): no claim of full erasure / hard purge yet.
- Play Console field still needs to be set out-of-band after deploy.

## Test plan
- [ ] Open `/account-deletion/` signed out — page loads (no redirect to sign-in)
- [ ] Confirm steps match Account → Delete my account + email confirm
- [ ] Confirm retention sections are accurate vs soft-delete
- [ ] `npm run test:ci -- --testPathPattern=AccountDeletionPage`
- [ ] After beta deploy, set Play Console Account deletion URL to the public HTTPS URLReviewed-on: #110

llm-fe/ANDROID.md

@@ -132,12 +132,20 @@ Out of band ops (not automated here):
 
 1. Google Play developer account
 2. Privacy policy URL (product site / legal)
-3. Data safety form (JWT auth, chat content, analytics if Tianji runs in WebView)
-4. Screenshots for phone (+ tablet if targeting)
-5. Upload `.aab` to **internal testing** track before production
+3. **Account deletion URL** (Data safety / Account deletion) → public page:
+   - Canonical: `https://hesychia.ai/account-deletion/`
+   - Legacy host until DNS cutover: `https://chat.aimloperations.com/account-deletion/`
+   - Capacitor HashRouter: `/#/account-deletion/`
+4. Data safety form (JWT auth, chat content, analytics if Tianji runs in WebView)
+5. Screenshots for phone (+ tablet if targeting)
+6. Upload `.aab` to **internal testing** track before production
+
+In-app delete remains Account → **Delete my account** (`DELETE /api/user/`). The public URL
+above is for Play reviewers and users who never open the app (#103).
 
 ## Related issues
 
 - [#20](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/20) — this Android wrap
 - [#21](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/21) — iOS (reuses this scaffolding)
 - [#22](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/22) / [#23](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/23) / [#24](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/24) — auth / WS / routing
+- [#103](https://git.aimloperations.com/ai_ml_operations/chat_web_app/issues/103) — Play public account-deletion URL