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/sessions/SessionPickerModal.svelte

@@ -6,6 +6,9 @@
   import { playbackPosition } from "$lib/stores/player";
   import { lmsSync, isLmsSession, macForSession } from "$lib/stores/lmsSync";
   import type { Session } from "$lib/api/types";
+  import { createLogger } from "$lib/utils/logger";
+
+  const log = createLogger("SessionPicker");
 
   interface Props {
     isOpen?: boolean;
@@ -41,7 +44,7 @@
         onClose();
       }
     } catch (error) {
-      console.error("Failed to select session:", error);
+      log.error("Failed to select session:", error);
       // Error is already stored in playbackMode store
     }
   }
@@ -67,7 +70,7 @@
         await lmsSync.fuseZone(masterMac, zoneMac);
       }
     } catch (error) {
-      console.error("Failed to toggle LMS zone:", error);
+      log.error("Failed to toggle LMS zone:", error);
       // Error is surfaced via the lmsSync store
     }
   }
@@ -79,7 +82,7 @@
         onClose();
       }
     } catch (error) {
-      console.error("Failed to transfer to local:", error);
+      log.error("Failed to transfer to local:", error);
       // Error is already stored in playbackMode store
     }
   }
@@ -91,7 +94,7 @@
         onClose();
       }
     } catch (error) {
-      console.error("Failed to disconnect:", error);
+      log.error("Failed to disconnect:", error);
       // Error is already stored in playbackMode store
     }
   }