feat: interface PIN, bulk disposition tagging, Google Drive delta scan, OCR memory fixes

- Interface PIN: optional session-level auth gate for the main scanner UI
  (Settings → Security → Interface PIN). Salted SHA-256 in config.json,
  rate-limited (5 attempts/5 min per IP). /view and viewer auth exempt.
  New /login page, before_request hook, GET/POST/DELETE /api/interface/pin,
  POST /api/interface/pin/verify, POST /api/interface/logout.

- Bulk disposition tagging: Select mode (filter bar "Vælg" button) reveals
  per-card checkboxes. Bulk tag bar at bottom of grid; POST /api/db/disposition/bulk.
  Disposition stats bar (total · unreviewed · retain · delete · % reviewed)
  updates after every save.

- Google Drive delta scan: uses Drive Changes API when delta is enabled.
  Per-user token stored as gdrive:{email} in delta.json. Load-then-merge
  save avoids racing with concurrent M365 token writes.

- PDF OCR OOM fix: render one page at a time with convert_from_path
  (first_page=N, last_page=N). Added _ocr_mem_ok() psutil guard (500 MB
  threshold) before each page render across scan_pdf, redact_fitz_pdf,
  redact_pdf.

- Email test message translation fix: routes/email.py returns structured
  {ok, method, recipients} instead of a hardcoded English string;
  scheduler.js builds the translated message client-side.

- Docs: CHANGELOG, README, TODO, MANUAL-EN, MANUAL-DA all updated.
  Lang files (en/da/de) extended with bulk, interface PIN, and SMTP keys.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

static/js/scheduler.js

@@ -334,7 +334,16 @@ async function stSmtpTest() {
       body:JSON.stringify({})});
     const d = await r.json();
     if (d.ok) {
-      if (st) { st.style.color='var(--accent)'; st.textContent='\u2714 ' + (d.message || t('m365_smtp_test_ok','Connection successful')); }
+      let msg;
+      if (d.method === 'graph') {
+        msg = t('m365_smtp_test_ok_graph','Test email sent via Microsoft Graph to') + ' ' + (d.recipients||[]).join(', ');
+      } else if (d.method === 'smtp') {
+        msg = t('m365_smtp_test_ok_smtp','Test email sent via SMTP to') + ' ' + (d.recipients||[]).join(', ');
+        if (d.graph_also_failed) msg += ' ' + t('m365_smtp_graph_also_failed','(⚠ Graph also failed — Mail.Send not granted)');
+      } else {
+        msg = d.message || t('m365_smtp_test_ok','Test email sent');
+      }
+      if (st) { st.style.color='var(--accent)'; st.textContent='\u2714 ' + msg; }
     } else {
       if (st) { st.style.color='var(--danger)'; st.textContent='\u2717 ' + (d.error || t('m365_smtp_test_fail','Connection failed')); }
     }