feat: add agor-pro commercial plugin crate and dual-repo infrastructure

agor-pro Tauri 2.x plugin (feature-gated via --features pro),
commercial Tauri config overlay, asymmetric test setup,
CI workflows (leak-check, commercial-build, PAT health),
pre-push hook, Makefile, CONTRIBUTING/MAINTENANCE/LICENSE-COMMERCIAL.

.github/workflows/pat-health.yml

@@ -0,0 +1,75 @@
+name: PAT Health Check
+
+on:
+  schedule:
+    - cron: '0 9 * * 1'  # Every Monday at 9am UTC
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  issues: write
+
+jobs:
+  check-pat:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check COMMUNITY_PAT validity
+        env:
+          COMMUNITY_PAT: ${{ secrets.COMMUNITY_PAT }}
+        run: |
+          if [ -z "$COMMUNITY_PAT" ]; then
+            echo "::error::COMMUNITY_PAT secret is not set"
+            echo "pat_valid=false" >> "$GITHUB_ENV"
+            exit 0
+          fi
+
+          status=$(curl -s -o /dev/null -w "%{http_code}" \
+            -H "Authorization: token $COMMUNITY_PAT" \
+            -H "Accept: application/vnd.github+json" \
+            https://api.github.com/user)
+
+          if [ "$status" -eq 200 ]; then
+            echo "COMMUNITY_PAT is valid (HTTP $status)"
+            echo "pat_valid=true" >> "$GITHUB_ENV"
+          else
+            echo "::error::COMMUNITY_PAT returned HTTP $status"
+            echo "pat_valid=false" >> "$GITHUB_ENV"
+          fi
+
+      - name: Create issue if PAT is invalid
+        if: env.pat_valid == 'false'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const title = 'COMMUNITY_PAT is invalid or missing';
+            const body = [
+              '## PAT Health Check Failed',
+              '',
+              'The weekly PAT health check detected that `COMMUNITY_PAT` is either missing or returning an error from the GitHub API.',
+              '',
+              '**Action required:** Rotate or re-create the PAT and update the repository secret.',
+              '',
+              `Run: ${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}`,
+            ].join('\n');
+
+            // Avoid duplicate issues
+            const existing = await github.rest.issues.listForRepo({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              state: 'open',
+              labels: 'pat-health',
+              per_page: 1,
+            });
+
+            if (existing.data.length > 0) {
+              console.log('Open PAT health issue already exists, skipping creation.');
+              return;
+            }
+
+            await github.rest.issues.create({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              title,
+              body,
+              labels: ['pat-health'],
+            });