feat: require operator sessions for privileged access (#258)

frontend/index.html

@@ -292,6 +292,7 @@ textarea { resize: vertical; min-height: 120px; }
   <div class="toolbar">
     <div class="status"><span class="dot"></span><span class="small" id="status">Live</span></div>
     <button id="refresh">Refresh</button>
+    <button id="sign-out" type="button">Sign out &amp; clear this device</button>
     <button id="open-palette">Command</button>
     <span class="small muted" id="clock"></span>
   </div>
@@ -747,6 +748,7 @@ textarea { resize: vertical; min-height: 120px; }
 
 <div class="footer">Creative AI-imbued UI • stackchain-dashboard</div>
 
+<script src="static/session.js"></script>
 <script src="static/markdown.js"></script>
 <script src="static/commands.js"></script>
 <script src="static/search-preview.js"></script>

frontend/service-worker.js

@@ -1,12 +1,13 @@
 const BASE = new URL('./', self.location.href).pathname;
 importScripts(BASE + 'static/background-issue-sync.js');
-const CACHE = 'stackchain-dashboard-shell-v15';
+const CACHE = 'stackchain-dashboard-shell-v16';
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const SHELL = [
   BASE,
   BASE + 'manifest.webmanifest',
   BASE + 'static/icons/stackchain-192.png',
   BASE + 'static/icons/stackchain-512.png',
+  BASE + 'static/session.js',
   BASE + 'static/markdown.js',
   BASE + 'static/commands.js',
   BASE + 'static/search-preview.js',
@@ -31,8 +32,25 @@ const SHELL = [
   BASE + 'static/background-issue-sync.js',
 ];
 
-async function fetchJson(url, options) {
-  const response = await fetch(new URL(url, self.location.origin), options);
+async function sessionCsrf() {
+  const response = await fetch(new URL(BASE + 'api/v1/session', self.location.origin), {
+    headers: { Accept: 'application/json' },
+  });
+  if (!response.ok) return '';
+  const payload = await response.json().catch(() => ({}));
+  return typeof payload.csrf_token === 'string' ? payload.csrf_token : '';
+}
+
+async function fetchJson(url, options = {}) {
+  const requestOptions = { ...options };
+  const method = String(options.method || 'GET').toUpperCase();
+  if (!['GET', 'HEAD', 'OPTIONS'].includes(method)) {
+    const headers = new Headers(options.headers || {});
+    const csrf = await sessionCsrf();
+    if (csrf) headers.set('X-CSRF-Token', csrf);
+    requestOptions.headers = headers;
+  }
+  const response = await fetch(new URL(url, self.location.origin), requestOptions);
   const payload = await response.json().catch(() => ({}));
   if (!response.ok) {
     const error = new Error(payload.error || payload.detail || 'Background issue delivery failed.');

frontend/session.js

@@ -0,0 +1,92 @@
+(function (root, factory) {
+  if (typeof module !== 'undefined' && module.exports) module.exports = factory;
+  else {
+    const base = new URL('./', root.location.href).pathname;
+    const originalFetch = root.fetch.bind(root);
+    const boundary = factory({
+      cookie: () => root.document.cookie,
+      origin: root.location.origin,
+      base,
+      fetchImpl: originalFetch,
+      localStorage: root.localStorage,
+      sessionStorage: root.sessionStorage,
+      indexedDB: root.indexedDB,
+      caches: root.caches,
+      location: root.location,
+      onExpired: () => root.dispatchEvent(new CustomEvent('stackchain:session-expired')),
+    });
+    root.fetch = boundary.fetch;
+    const attach = () => {
+      const button = root.document.getElementById('sign-out');
+      if (button) button.addEventListener('click', () => boundary.signOut());
+    };
+    if (root.document.readyState === 'loading') root.document.addEventListener('DOMContentLoaded', attach);
+    else attach();
+    root.stackchainSession = boundary;
+  }
+})(typeof window !== 'undefined' ? window : this, function createSessionBoundary({
+  cookie, origin, base, fetchImpl, localStorage, sessionStorage, indexedDB, caches, location,
+  onExpired = () => {},
+}) {
+  const SAFE_METHODS = new Set(['GET', 'HEAD', 'OPTIONS']);
+
+  function csrfToken() {
+    const entry = String(cookie?.() || '').split(';')
+      .map(value => value.trim())
+      .find(value => value.startsWith('stackchain_csrf='));
+    return entry ? decodeURIComponent(entry.slice('stackchain_csrf='.length)) : '';
+  }
+
+  function isSameOrigin(input) {
+    try { return new URL(String(input?.url || input), origin).origin === origin; }
+    catch (_error) { return false; }
+  }
+
+  async function sessionFetch(input, options = {}) {
+    const method = String(options.method || input?.method || 'GET').toUpperCase();
+    const requestOptions = { ...options };
+    if (!SAFE_METHODS.has(method) && isSameOrigin(input)) {
+      const headers = new Headers(options.headers || input?.headers || {});
+      const csrf = csrfToken();
+      if (csrf) headers.set('X-CSRF-Token', csrf);
+      requestOptions.headers = headers;
+    }
+    const response = await fetchImpl(input, requestOptions);
+    if (response.status === 401) onExpired();
+    return response;
+  }
+
+  function removeDashboardStorage(storage) {
+    if (!storage) return;
+    const keys = [];
+    try {
+      for (let index = 0; index < storage.length; index += 1) {
+        const key = storage.key(index);
+        if (key?.startsWith('stackchain.')) keys.push(key);
+      }
+      keys.forEach(key => storage.removeItem(key));
+    } catch (_error) { /* Cookie invalidation still protects server data. */ }
+  }
+
+  async function clearPrivateDeviceData() {
+    removeDashboardStorage(localStorage);
+    if (sessionStorage !== localStorage) removeDashboardStorage(sessionStorage);
+    try { indexedDB?.deleteDatabase('stackchain-background-outbox-v1'); }
+    catch (_error) { /* Continue clearing other dashboard state. */ }
+    try {
+      const keys = await caches?.keys?.() || [];
+      await Promise.all(keys.filter(key => key.startsWith('stackchain-dashboard-')).map(key => caches.delete(key)));
+    } catch (_error) { /* A later service-worker activation can clear stale caches. */ }
+  }
+
+  async function signOut() {
+    try {
+      await sessionFetch(base + 'api/v1/session', { method: 'DELETE' });
+    } finally {
+      await clearPrivateDeviceData();
+      location.assign(base + 'login');
+    }
+  }
+
+  return { fetch: sessionFetch, signOut, clearPrivateDeviceData };
+});