Add OCR language override setting

Operators can now choose Tesseract language pack(s) per profile via a
sidebar select (#optOcrLang) and profile editor (#peOptOcrLang). Presets:
dan+eng (default), dan, eng, dan+eng+deu, dan+eng+swe, dan+eng+fra. The
ocr_lang option flows from the UI through all three scan engines (M365
files/attachments, Google Drive, Gmail) down to document_scanner.scan_pdf
and scan_image — including the spawned PDF-OCR subprocess worker.

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

tests/test_google_scan.py

@@ -193,7 +193,7 @@ class TestRunGoogleScan:
         monkeypatch.setattr(gdpr_scanner, "broadcast",
                             lambda evt, data=None: events.append((evt, data or {})))
         monkeypatch.setattr(gdpr_scanner, "_scan_bytes",
-                            lambda data, name: scan_bytes_result or {
+                            lambda data, name, **kw: scan_bytes_result or {
                                 "cprs": [], "pii_counts": None, "emails": [], "phones": []
                             })
         monkeypatch.setattr(checkpoint, "_load_checkpoint", lambda *a, **kw: None)