Polish settings UI and add Gitea Actions CI gate

Settings: highlight the selected adapter, restyle radios/password/select
for the dark theme, and keep saved settings scoped to the chosen adapter.
CI: run npm test + gitleaks on push/PR so the suite is an actual gate.

.gitea/workflows/ci.yml

@@ -0,0 +1,34 @@
+---
+# Homelab CI for SwipeAnything
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  test:
+    name: Unit tests
+    runs-on: [homelab, self-hosted, linux]
+    container:
+      image: node:20-bookworm
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install
+        run: npm ci
+      - name: Test
+        run: npm test
+
+  secret-scan:
+    name: Gitleaks
+    runs-on: [homelab, self-hosted, linux, heavy]
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Gitleaks
+        run: |
+          docker run --rm -v "$PWD:/repo" ghcr.io/gitleaks/gitleaks:latest \
+            detect --source /repo --no-banner --redact