Enable beta auto-deploy + Tianji beta ID / consent-gated events (#35) (#42)

## Summary

Closes #35.

- **Flip deploy workflows** (mirror `dta_webapp`): push/merge to `master` → auto-deploy **beta**; **Deploy Prod** is `workflow_dispatch` only
- **Tianji**: `REACT_APP_TIANJI_WEBSITE_ID` + `REACT_APP_DEPLOY_ENV` in `.env.production` / `.env.beta`; Tracker loads page views always on prod/beta
- **Consent policy**: page views always live; custom events / identify gated via `analyticsConsent` + `AnalyticsConsentBanner` + `trackEvent`/`identifyUser` helpers (call sites remain #36)
- Remove invalid Tianji `<script>` from `index.tsx` (Tracker component owns injection)
- README documents beta auto / prod button + Tianji policy

## Ops note — beta Tianji website ID

Prod ID unchanged: `cm7x7m52m03kbddswbswrt17y`.

`.env.beta` has `REACT_APP_TIANJI_WEBSITE_ID=` empty until a **Hesychia Beta** website is created in Tianji (workspace `cm7w8087y020lddswyhamadj2`). Paste the new id into `.env.beta` before beta page views show under a distinct site.

## Test plan

- [x] `npm run test:ci` (106 tests)
- [ ] Create Hesychia Beta Tianji website; set `REACT_APP_TIANJI_WEBSITE_ID` in `.env.beta`
- [ ] Merge to master → Deploy Beta runs; prod does **not** auto-deploy
- [ ] Manual Run workflow on Deploy Prod still works
- [ ] Beta build hits `beta.chatbackend` REST/WS; static root `/var/www/beta.chat.aimloperations/html` (8083)
- [ ] Prod/beta: tracker.js loads without accepting consent; banner shows until Accept/Decline; `trackEvent` only fires after AcceptReviewed-on: #42

.gitea/workflows/deploy-prod.yml

@@ -1,15 +1,31 @@
 name: Deploy Prod
 
-# Runs after Unit Tests completes on master. Direct pushes only (not PRs).
+# Manual prod deploy only (mirrors dta_webapp). Push to master deploys beta.
 on:
-  workflow_run:
-    workflows: [Unit Tests]
-    types: [completed]
-    branches: [master]
+  workflow_dispatch: {}
 
 jobs:
-  deploy:
-    if: gitea.event.workflow_run.conclusion == 'success' && gitea.event.workflow_run.event == 'push'
+  unit-tests:
+    runs-on: self-hosted
+    defaults:
+      run:
+        working-directory: llm-fe
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run unit tests
+        run: npm run test:ci
+
+  deploy-prod:
+    needs: unit-tests
     runs-on: self-hosted
     env:
       SERVER_INFRA_ROOT: /home/westfarn/Documents/repos/server-infra
@@ -19,4 +35,4 @@ jobs:
           "$SERVER_INFRA_ROOT/scripts/deploy.sh" \
             --app chat_web_app \
             --env prod \
-            --ref "${{ gitea.event.workflow_run.head_sha }}"
+            --ref "${{ gitea.sha }}"