fix(mpv): gate socket logs by debug level

- Gate MPV socket reconnect-attempt, close, and error logs behind SUBMINER_LOG_LEVEL=debug.\n- Preserve MPV reconnect behavior and success-path logging unaffected.\n- Update TASK-33 metadata/status with implementation summary.

backlog/tasks/task-33 - Restrict-mpv-socket-connection-logs-to-debug-mode-in-Electron.md

@@ -1,9 +1,10 @@
 ---
 id: TASK-33
 title: Restrict mpv socket connection logs to debug mode in Electron
-status: To Do
+status: Done
 assignee: []
 created_date: '2026-02-13 19:39'
+updated_date: '2026-02-16 03:05'
 labels:
   - electron
   - logging
@@ -30,6 +31,12 @@ In normal operation, Electron should not spam logs while waiting for mpv socket
 - [ ] #6 If connection fails and retries continue, keep a debug-only or final-error log policy consistent with existing logging severity conventions.
 <!-- AC:END -->
 
+## Final Summary
+
+<!-- SECTION:FINAL_SUMMARY:BEGIN -->
+Implemented debug-gated MPV socket noise suppression in normal mode while preserving reconnect behavior. Added an internal check for SUBMINER_LOG_LEVEL==='debug' and wrapped socket reconnect-attempt, close, and error logs so regular startup/reconnect loops no longer emit per-interval messages unless debug logging is enabled. Kept existing connection-success flow unchanged. Validation: `pnpm run build`, `node --test dist/core/services/mpv-service.test.js`.
+<!-- SECTION:FINAL_SUMMARY:END -->
+
 ## Definition of Done
 <!-- DOD:BEGIN -->
 - [ ] #1 No connection-attempt/connect-wait logs are produced in non-debug mode.

src/core/services/mpv-service.ts

@@ -19,6 +19,10 @@ import {
 } from "./mpv-transport";
 import { resolveCurrentAudioStreamIndex } from "./mpv-state";
 
+const isDebugLoggingEnabled = (): boolean => {
+  return (process.env.SUBMINER_LOG_LEVEL || "").toLowerCase() === "debug";
+};
+
 export {
   MPV_REQUEST_ID_SECONDARY_SUB_VISIBILITY,
 } from "./mpv-protocol";
@@ -129,11 +133,15 @@ export class MpvIpcClient implements MpvClient {
         this.processBuffer();
       },
       onError: (err: Error) => {
+        if (isDebugLoggingEnabled()) {
           console.error("MPV socket error:", err.message);
+        }
         this.failPendingRequests();
       },
       onClose: () => {
+        if (isDebugLoggingEnabled()) {
           console.log("MPV socket closed");
+        }
         this.connected = false;
         this.connecting = false;
         this.socket = null;
@@ -194,9 +202,11 @@ export class MpvIpcClient implements MpvClient {
       getReconnectTimer: () => this.deps.getReconnectTimer(),
       setReconnectTimer: (timer) => this.deps.setReconnectTimer(timer),
       onReconnectAttempt: (attempt, delay) => {
+        if (isDebugLoggingEnabled()) {
           console.log(
             `Attempting to reconnect to MPV (attempt ${attempt}, delay ${delay}ms)...`,
           );
+        }
       },
       connect: () => {
         this.connect();