feat: add comprehensive CI/CD pipeline

Adds GitHub Actions workflows for CI, maintenance, and releases with multi-platform testing matrix.

.github/workflows/maintenance.yml

@@ -0,0 +1,51 @@
+name: Scheduled Maintenance
+
+on:
+  schedule:
+    - cron: '0 9 * * 1'  # Weekly Monday 9am UTC
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+jobs:
+  dependency-check:
+    name: Check Dependencies
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+      - name: Check for outdated packages
+        run: npm outdated || true
+
+  security-audit:
+    name: Security Audit
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+      - name: Run security audit
+        run: |
+          if [ -f package-lock.json ]; then
+            npm ci
+            npm audit --audit-level=high
+          else
+            echo "No package-lock.json found; skipping npm audit"
+          fi
+
+  stale:
+    name: Stale Issues/PRs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          stale-issue-message: 'This issue is stale due to inactivity.'
+          stale-pr-message: 'This PR is stale due to inactivity.'
+          days-before-stale: 30
+          days-before-close: 7