feat: cookie consent extension support (ARCHIVR_COOKIE_EXT)

Mirrors the uBlock Origin Lite integration exactly:

Backend:
- singlefile.rs: resolve_cookie_ext_config() reads ARCHIVR_COOKIE_CONSENT
  (default true) + ARCHIVR_COOKIE_EXT path; extension paths comma-joined
  into --load-extension / --disable-extensions-except so uBlock and cookie
  ext can coexist; SaveResult.cookie_ext_skipped tracks miss
- database.rs: cookie_ext_enabled column on instance_settings (DEFAULT 1);
  idempotent ALTER TABLE migration; get/update wired through
- capture.rs: CaptureConfig.cookie_ext_enabled: Option<bool>; threaded to
  singlefile::save(); cookie_ext_skipped surfaced in CaptureResult
- routes.rs: CaptureBody + UpdateInstanceSettingsBody get cookie_ext_enabled;
  capture handler resolves effective value (body overrides global); notes_json
  only includes skipped fields that are true; GET instance-settings includes
  cookie_ext_available from env path check

Frontend:
- api.js: submitCapture forwards cookie_ext_enabled
- SettingsView.jsx: 'I Still Don't Care About Cookies' card in Extensions
  tab; always-active toggle (user can disable even when ext not installed);
  amber 'Not configured' hint + ARCHIVR_COOKIE_EXT guidance when unavailable
- CaptureDialog.jsx: 'Block cookie banners' toggle in Advanced options;
  always shown with amber hint when ext not configured; defaults from
  global setting

Operator setup: download + unzip the extension from GitHub releases, set
ARCHIVR_COOKIE_EXT=/path/to/unpacked/ext. No Node daemon needed.

frontend/src/api.js

@@ -102,6 +102,7 @@ export async function submitCapture(archiveId, locator, quality = null, extensio
   if (extensions) {
     if (typeof extensions.ublock_enabled === 'boolean') payload.ublock_enabled = extensions.ublock_enabled
     if (typeof extensions.reader_mode === 'boolean') payload.reader_mode = extensions.reader_mode
+    if (typeof extensions.cookie_ext_enabled === 'boolean') payload.cookie_ext_enabled = extensions.cookie_ext_enabled
   }
   const res = await fetch(`/api/archives/${archiveId}/captures`, {
     method: "POST",

frontend/src/components/CaptureDialog.jsx

@@ -116,18 +116,24 @@ export default function CaptureDialog({ open, archiveId, onClose, onCaptured, on
   const [advancedOpen, setAdvancedOpen] = useState(false)
   // null = use server default; true/false = per-session override
   const [ublockOverride, setUblockOverride] = useState(null)
-  // Server-side global default (loaded on mount, null until loaded)
-  const [globalUblock, setGlobalUblock] = useState(null)
+  // Server-side global settings (loaded on mount, null until loaded)
+  const [globalSettings, setGlobalSettings] = useState(null)
+  // Cookie consent: session-level only, initialized from server default
+  const [cookieExtEnabled, setCookieExtEnabled] = useState(true)
 
-  // Load global uBlock setting from server once on mount
+  // Load global settings from server once on mount
   useEffect(() => {
     getInstanceSettings()
-      .then(s => setGlobalUblock(s.ublock_enabled ?? true))
-      .catch(() => setGlobalUblock(true)) // safe default
+      .then(s => {
+        setGlobalSettings(s)
+        setCookieExtEnabled(s.cookie_ext_enabled ?? true)
+      })
+      .catch(() => setGlobalSettings({}))
   }, [])
 
   // Effective uBlock for this session
-  const ublockEnabled = ublockOverride !== null ? ublockOverride : (globalUblock ?? true)
+  const ublockEnabled = ublockOverride !== null ? ublockOverride : (globalSettings?.ublock_enabled ?? true)
+
   // Reader mode: off by default, per-session only
   const [readerMode, setReaderMode] = useState(false)
 
@@ -242,7 +248,7 @@ export default function CaptureDialog({ open, archiveId, onClose, onCaptured, on
     const qual = item.quality || 'best'
     setItems(prev => prev.map(it => it.id === item.id ? { ...it, status: 'submitting', error: null } : it))
     try {
-      const extensions = { ublock_enabled: ublockEnabled, reader_mode: readerMode }
+      const extensions = { ublock_enabled: ublockEnabled, reader_mode: readerMode, cookie_ext_enabled: cookieExtEnabled }
       const job = await submitCapture(aid, loc, qual, extensions)
       setItems(prev => prev.map(it =>
         it.id === item.id ? { ...it, status: 'running', jobUid: job.job_uid, archiveId: aid } : it
@@ -397,6 +403,25 @@ export default function CaptureDialog({ open, archiveId, onClose, onCaptured, on
                   <span className="ext-toggle-knob" />
                 </button>
               </label>
+              <label className="capture-ext-row" style={{ marginTop: 8 }}>
+                <span className="capture-ext-label">
+                  <span className="capture-ext-name">Block cookie banners</span>
+                  <span className="capture-ext-desc">Dismiss cookie consent banners during this capture</span>
+                  {!globalSettings?.cookie_ext_available && (
+                    <span className="capture-ext-hint">Not configured &mdash; set <code>ARCHIVR_COOKIE_EXT</code></span>
+                  )}
+                </span>
+                <button
+                  type="button"
+                  role="switch"
+                  aria-checked={cookieExtEnabled}
+                  className={`ext-toggle ext-toggle--sm${cookieExtEnabled ? ' ext-toggle--on' : ''}`}
+                  onClick={() => setCookieExtEnabled(v => !v)}
+                  aria-label="Toggle cookie banner blocking for this capture"
+                >
+                  <span className="ext-toggle-knob" />
+                </button>
+              </label>
               <label className="capture-ext-row" style={{ marginTop: 8 }}>
                 <span className="capture-ext-label">
                   <span className="capture-ext-name">Reader mode</span>

frontend/src/components/SettingsView.jsx

@@ -669,10 +669,26 @@ function ExtensionsTab() {
     }
   }
 
+  async function toggleCookieExt(val) {
+    setSaving(true)
+    setMsg(null)
+    try {
+      await updateInstanceSettings({ cookie_ext_enabled: val })
+      setSettings(s => ({ ...s, cookie_ext_enabled: val }))
+      setMsg({ ok: true, text: 'Saved.' })
+    } catch (e) {
+      setMsg({ ok: false, text: e.message })
+    } finally {
+      setSaving(false)
+    }
+  }
+
   if (loading) return <div className="muted">Loading\u2026</div>
 
   const extAvailable = settings?.ublock_ext_available ?? false
   const extEnabled = settings?.ublock_enabled ?? true
+  const cookieExtAvailable = settings?.cookie_ext_available ?? false
+  const cookieExtEnabled = settings?.cookie_ext_enabled ?? true
 
   return (
     <div style={{ maxWidth: 560 }}>
@@ -712,6 +728,34 @@ function ExtensionsTab() {
           </div>
         </div>
 
+        <div className="ext-card">
+          <div className="ext-card-header">
+            <div className="ext-card-info">
+              <span className="ext-card-name">I Still Don&rsquo;t Care About Cookies</span>
+              <span className="ext-card-desc">
+                Dismiss cookie consent banners during archiving.
+              </span>
+              {!cookieExtAvailable && (
+                <span className="ext-card-hint">
+                  Not configured &mdash; set <code>ARCHIVR_COOKIE_EXT</code> to the
+                  unpacked extension directory to enable.
+                </span>
+              )}
+            </div>
+            <button
+              type="button"
+              role="switch"
+              aria-checked={cookieExtEnabled}
+              className={`ext-toggle${cookieExtEnabled ? ' ext-toggle--on' : ''}`}
+              onClick={() => toggleCookieExt(!cookieExtEnabled)}
+              disabled={saving}
+              aria-label="Toggle I Still Don't Care About Cookies"
+            >
+              <span className="ext-toggle-knob" />
+            </button>
+          </div>
+        </div>
+
         {msg && <div className={`form-msg form-msg--${msg.ok ? 'ok' : 'err'}`}>{msg.text}</div>}
       </div>
     </div>