refactor(logging): route frontend console calls through the logger

TRACES: | DR-204

484 ungated `console.*` calls across 63 non-test frontend files shipped to
end users with no way to turn them off. Mechanical substitution, no control
flow, error handling or message semantics changed:

  console.log / console.debug -> log.debug
  console.info                -> log.info
  console.warn                -> log.warn
  console.error               -> log.error

Hand-written `"[Scope] …"` prefixes are dropped where the logger's scope
now carries them; scope names that already existed are preserved verbatim
(`[Auth]`, `[VideoPlayer]`, `[PiP]`, …) and inferred from the filename
where a file had none. `src/routes/player/[id]/+page.svelte` keeps its
`NextEpisode` and `AutoPlay` sub-scopes as separate loggers rather than
flattening them into the page scope.

`grep -rn 'console\.' src/` now matches nothing outside the tests and the
facade itself.

src/routes/settings/+page.svelte

@@ -29,6 +29,9 @@
   } from "$lib/services/networkType";
   import { experimentalNativeVideo } from "$lib/stores/nativeVideo";
   import { getPlaybackCapabilities } from "$lib/services/playbackCapabilities";
+  import { createLogger } from "$lib/utils/logger";
+
+  const log = createLogger("SettingsPage");
 
   const episodeLimitOptions = [
     { value: 0, label: "Unlimited" },
@@ -153,7 +156,7 @@
       // Load cache stats in parallel but don't block on it
       loadCacheStats();
     } catch (e) {
-      console.error("Failed to load settings:", e);
+      log.error("Failed to load settings:", e);
     } finally {
       loading = false;
     }
@@ -164,7 +167,7 @@
       cacheLoading = true;
       cacheStats = await getCacheStats();
     } catch (e) {
-      console.error("Failed to load cache stats:", e);
+      log.error("Failed to load cache stats:", e);
     } finally {
       cacheLoading = false;
     }
@@ -176,7 +179,7 @@
       // Reload stats to reflect new limit
       await loadCacheStats();
     } catch (e) {
-      console.error("Failed to set cache limit:", e);
+      log.error("Failed to set cache limit:", e);
     }
   }
 
@@ -186,7 +189,7 @@
       await clearCache();
       await loadCacheStats();
     } catch (e) {
-      console.error("Failed to clear cache:", e);
+      log.error("Failed to clear cache:", e);
     } finally {
       clearingCache = false;
     }
@@ -214,7 +217,7 @@
     try {
       await commands.playerSetAudioSettings(settings);
     } catch (e) {
-      console.error("Failed to save audio settings:", e);
+      log.error("Failed to save audio settings:", e);
     }
   }
 
@@ -222,7 +225,7 @@
     try {
       await commands.playerSetVideoSettings(videoSettings);
     } catch (e) {
-      console.error("Failed to save video settings:", e);
+      log.error("Failed to save video settings:", e);
     }
   }
 
@@ -234,7 +237,7 @@
       // rather than at the next network change.
       await reportNetworkState();
     } catch (e) {
-      console.error("Failed to save download settings:", e);
+      log.error("Failed to save download settings:", e);
     }
   }