Recover unfinished scans so their items aren't stranded

get_session_items / get_open_items / latest_scan_id all require
finished_at IS NOT NULL, but the M365 and Google engines return early
on abort (skipping finish_scan) and a process kill mid-scan (deploy,
OOM, crash) never reaches it either. Result on prod: 41/42 scans had
finished_at NULL, so 291 already-saved flagged items were invisible —
the grid showed nothing.

- finalize_orphan_scans(): finalises every finished_at-NULL scan; runs
  once at startup before the scheduler (nothing is scanning at boot, so
  any unfinished scan is dead). Recovers existing stranded items and
  guards against future mid-scan restarts.
- run_scan: finalise the DB scan on the abort early-return too, so a
  stopped scan's items stay visible without waiting for a restart.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

gdpr_db.py

@@ -29,11 +29,14 @@ Usage (from gdpr_scanner.py)
 
 import hashlib
 import json
+import logging
 import sqlite3
 import time
 from pathlib import Path
 from typing import Iterator
 
+logger = logging.getLogger(__name__)
+
 from pathlib import Path as _P
 _DATA_DIR = _P.home() / ".gdprscanner"
 _DATA_DIR.mkdir(exist_ok=True)
@@ -432,6 +435,33 @@ class ScanDB:
 
         c.commit()
 
+    def finalize_orphan_scans(self) -> int:
+        """Finalise scans left unfinished by a crash, kill, or mid-scan restart.
+
+        After a fresh process start nothing is scanning, so any scan still
+        carrying finished_at IS NULL is dead — the process that owned it is gone.
+        Its already-saved flagged_items were stranded: both get_session_items
+        and get_open_items require finished_at, so those items are invisible and
+        effectively lost.  Finalising the orphans on startup makes them show up
+        and prevents permanent data loss from interrupted scans (the M365 and
+        Google engines return early on abort and never reach finish_scan; only
+        the file scan finalises in a finally block).
+
+        Safe to call only when no scan is running (i.e. at startup).  Returns the
+        number of scans finalised.
+        """
+        rows = self._connect().execute(
+            "SELECT id, total_scanned FROM scans WHERE finished_at IS NULL"
+        ).fetchall()
+        count = 0
+        for sid, total in rows:
+            try:
+                self.finish_scan(sid, total or 0)
+                count += 1
+            except Exception as e:
+                logger.warning("[db] finalize_orphan_scans: scan %s failed: %s", sid, e)
+        return count
+
     # ── Query helpers ─────────────────────────────────────────────────────────
 
     def latest_scan_id(self) -> int | None: