chore(hygiene): Phase 4 guardrails — noUnusedLocals/Parameters + dead-code sweep

Enable tsconfig noUnusedLocals + noUnusedParameters (permanent guardrail: every tsc/
build now flags re-accumulated dead code). Fixed the 8 violations that surfaced, all
genuine dead code:
- Sidebar: deleted unused SORT_IDS/SHOW_IDS/rollSeed consts + the dead Toggle component
  (+ its now-unused Switch import).
- PlexBrowse: dropped the unused onClearSearch prop (Props + destructure + App call site).
- VideoEditor: dropped the unused map index; notifications: deleted the dead back-compat
  toast(); storage: deleted the unused non-account usePersistedState (+ readJSON import).
- SavedViewsWidget: deleted the dead loadDefaultViewFilters export (App loads the default
  view inline; resolves the last knip unused-export → knip now clean).

Backend: added backend/ruff.toml (ignore E402 — intentional pre-import setup in main.py)
and fixed the 6 E702/E741 style items (_vtt_s_to_ts semicolons, ambiguous `l` loop vars)
so ruff is green. localdev boots; Feed/Plex/sidebar render; 0 console errors.

backend/app/routes/downloads.py

@@ -752,7 +752,7 @@ def list_links(
         .scalars()
         .all()
     )
-    return [linksmod.owner_view(l) for l in rows]
+    return [linksmod.owner_view(row) for row in rows]
 
 
 @router.post("/{job_id}/links")

backend/app/routes/plex.py

@@ -1346,11 +1346,15 @@ def _vtt_ts_to_s(ts: str) -> float:
 
 def _vtt_s_to_ts(x: float) -> str:
     x = max(0.0, x)
-    h = int(x // 3600); x -= h * 3600
-    m = int(x // 60); x -= m * 60
-    s = int(x); ms = int(round((x - s) * 1000))
+    h = int(x // 3600)
+    x -= h * 3600
+    m = int(x // 60)
+    x -= m * 60
+    s = int(x)
+    ms = int(round((x - s) * 1000))
     if ms >= 1000:
-        s += 1; ms -= 1000
+        s += 1
+        ms -= 1000
     return f"{h:02d}:{m:02d}:{s:02d}.{ms:03d}"
 
 

backend/app/sync/subscriptions.py

@@ -34,9 +34,9 @@ def _external_links(branding: dict) -> list | None:
     channel = branding.get("channel", {})
     links = channel.get("links") or []
     out = [
-        {"title": l.get("title"), "url": l.get("url")}
-        for l in links
-        if isinstance(l, dict) and l.get("url")
+        {"title": item.get("title"), "url": item.get("url")}
+        for item in links
+        if isinstance(item, dict) and item.get("url")
     ]
     return out or None
 

backend/ruff.toml

@@ -0,0 +1,6 @@
+# Ruff config for the Siftlode backend. Keeps ruff's default rule set (E4/E7/E9 + F = the
+# high-signal pyflakes/pycodestyle checks that catch real dead code + bugs), but ignores E402:
+# a handful of modules (e.g. main.py) deliberately run setup — logging config, sys.path — before
+# importing route modules, so "module import not at top of file" is intentional there, not cruft.
+[lint]
+ignore = ["E402"]