Move CI workflows to repo root .gitea/workflows/ (Gitea requires root location)

- 6 per-product CI workflows with path filters
- P1: Rust (cargo test + clippy + fmt)
- P2: Go agent (go test + vet) + Node SaaS (tsc + npm test)
- P3-P6: Node (npm ci + tsc + npm test)
- Removed old per-product .gitea dirs (Gitea ignores non-root workflows)

.gitea/workflows/ci-p3-alert.yml

@@ -0,0 +1,29 @@
+name: CI — P3 Alert
+on:
+  push:
+    branches: [main]
+    paths: ['products/03-alert-intelligence/**']
+  pull_request:
+    paths: ['products/03-alert-intelligence/**']
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Install deps
+        run: npm ci
+        working-directory: products/03-alert-intelligence
+
+      - name: Type check
+        run: npx tsc --noEmit
+        working-directory: products/03-alert-intelligence
+
+      - name: Test
+        run: npm test
+        working-directory: products/03-alert-intelligence