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/api/repository-client.ts

@@ -19,6 +19,9 @@ import type {
   PlaylistEntry,
   PlaylistCreatedResult,
 } from "./types";
+import { createLogger } from "$lib/utils/logger";
+
+const log = createLogger("RepositoryClient");
 
 /**
  * Repository client - thin wrapper over Rust HybridRepository
@@ -39,14 +42,14 @@ export class RepositoryClient {
     accessToken: string,
     serverId: string
   ): Promise<string> {
-    console.log("[RepositoryClient] Creating Rust repository...");
+    log.debug("Creating Rust repository...");
     this.handle = await commands.repositoryCreate(serverUrl, userId, accessToken, serverId);
 
     // Store for URL construction
     this._serverUrl = serverUrl;
     this._accessToken = accessToken;
 
-    console.log("[RepositoryClient] Repository created with handle:", this.handle);
+    log.debug("Repository created with handle:", this.handle);
     return this.handle;
   }