Harden dependencies and add continuous verification

.github/workflows/ci.yml

@@ -0,0 +1,44 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  verify:
+    name: Lint, test, build, and audit
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+
+      - name: Install locked dependencies
+        run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+      - name: Run deterministic test suite
+        run: npm test
+
+      - name: Build production bundle
+        run: npm run build
+
+      - name: Audit production dependencies
+        run: npm audit --omit=dev --audit-level=high

README.md

@@ -1,5 +1,7 @@
 # SourceDeck
 
+[![CI](https://github.com/Xyloth/SourceDeck/actions/workflows/ci.yml/badge.svg)](https://github.com/Xyloth/SourceDeck/actions/workflows/ci.yml)
+
 SourceDeck is a local-first evidence command center for high-stakes meetings.
 It turns PDFs, Word documents, notes, and record folders into searchable
 evidence cards with exact quotes, source references, issue maps, meeting