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/lib/components/library/GenericGenreBrowser.svelte

@@ -13,6 +13,9 @@
   import { useServerReachabilityReload } from "$lib/composables/useServerReachabilityReload";
   import { useOfflineFilterReload } from "$lib/composables/useOfflineFilterReload";
   import type { Genre, MediaItem, ItemType } from "$lib/api/types";
+  import { createLogger } from "$lib/utils/logger";
+
+  const log = createLogger("GenericGenreBrowser");
 
   /**
    * Generic genre browser supporting Movies, Music Albums, and TV Series
@@ -92,7 +95,7 @@
       genres = result.sort((a, b) => a.name.localeCompare(b.name));
       applyFilter();
     } catch (e) {
-      console.error("Failed to load genres:", e);
+      log.error("Failed to load genres:", e);
     } finally {
       loading = false;
     }
@@ -115,7 +118,7 @@
       });
       genreItems = result.items;
     } catch (e) {
-      console.error("Failed to load genre items:", e);
+      log.error("Failed to load genre items:", e);
     } finally {
       loadingItems = false;
     }