Fix playlist status page, dedup delete-by-path bug, duplicate scan rows; add public IP dashboard card

Playlist detail page's status section (and the new two-column compare
view) was never rendering: the router awaited status_service.playlist_status(),
but that function is plain sync, so awaiting its dict return raised
"object dict can't be used in 'await' expression" on every load, silently
caught and shown as a generic fetch error. Removed the erroneous await.

find-fuzzy-dupes.py's --apply and --apply-pairs both deleted by a `path::`
regex query even though the beets id was already available in scope --
same mixed-path-storage issue (pre/post beets-2.11-upgrade items store
absolute vs. library-relative paths) dedup-library.sh already worked
around by deleting via id instead. This silently failed to match for most
confirmed fuzzy-audio deletions (verified: 19 of 20 in one run). Added a
delete_id column to dedup_candidates, threaded through the scan/apply
pipeline, and switched both delete call sites to `id:`.

Dedup scans also never checked whether a pair was already sitting in the
pending list, so every re-scan (including the daily schedule) added a new
row for the same unreviewed duplicate -- cleaned up 38 redundant rows
already in production and added a check so future scans skip a pair
that's already pending.

Dashboard gets a Public IP stat card (cached 10 min, fetched via ipify)
as a quick confidence check that outbound traffic is actually routed
through gluetun's VPN and not the home connection.

app/services/dedup_review_service.py

@@ -41,6 +41,22 @@ def _is_pair_ignored(db, path_a: str, path_b: str) -> bool:
     return db.execute(query).first() is not None
 
 
+def _is_pair_already_pending(db, keep_path: str, delete_path: str) -> bool:
+    """True if this exact keep/delete pair is already sitting in the
+    pending list from an earlier scan. Without this, every re-scan of a
+    duplicate the user hasn't reviewed yet (e.g. the daily scheduled scan)
+    added a brand-new row for the same pair, so it piled up multiple
+    identical entries in the table instead of just staying as one."""
+    query = select(DedupCandidate.id).where(
+        DedupCandidate.applied == False,  # noqa: E712
+        DedupCandidate.confirmed == False,  # noqa: E712
+        DedupCandidate.ignored == False,  # noqa: E712
+        DedupCandidate.keep_path == keep_path,
+        DedupCandidate.delete_path == delete_path,
+    ).limit(1)
+    return db.execute(query).first() is not None
+
+
 def _parse_json_lines(output: str) -> list[dict]:
     candidates = []
     for line in output.splitlines():
@@ -77,23 +93,34 @@ async def _run_scan(job_key: str, script_name: str, triggered_by: str) -> DedupR
         db.refresh(dedup_run)
 
         skipped_ignored = 0
+        skipped_duplicate = 0
         for c in candidates:
             if _is_pair_ignored(db, c["keep_path"], c["delete_path"]):
                 skipped_ignored += 1
                 continue
+            if _is_pair_already_pending(db, c["keep_path"], c["delete_path"]):
+                skipped_duplicate += 1
+                continue
             db.add(
                 DedupCandidate(
                     dedup_run_id=dedup_run.id,
                     pass_name=c.get("pass", "unknown"),
                     keep_path=c["keep_path"],
                     delete_path=c["delete_path"],
+                    delete_id=c.get("delete_id"),
                     delete_size_bytes=c.get("delete_size_bytes"),
                 )
             )
+            # Flush (not commit) so a duplicate pair emitted twice within
+            # this same scan's own output -- e.g. two passes agreeing on
+            # the same file -- is caught by the next iteration's check too,
+            # not just duplicates from a previous scan's committed rows.
+            db.flush()
         db.commit()
         db.refresh(dedup_run)
-        if skipped_ignored:
-            dedup_run.kept = (dedup_run.kept or 0) + skipped_ignored
+        skipped_total = skipped_ignored + skipped_duplicate
+        if skipped_total:
+            dedup_run.kept = (dedup_run.kept or 0) + skipped_total
             db.commit()
             db.refresh(dedup_run)
         return dedup_run
@@ -144,7 +171,8 @@ def _write_apply_args(script_name: str, script: str, group: list[DedupCandidate]
         pairs_file.parent.mkdir(parents=True, exist_ok=True)
         pairs_file.write_text(
             "\n".join(
-                json.dumps({"keep_path": c.keep_path, "delete_path": c.delete_path}) for c in group
+                json.dumps({"keep_path": c.keep_path, "delete_path": c.delete_path, "delete_id": c.delete_id})
+                for c in group
             )
             + "\n"
         )