fix(logger): use app.isPackaged for log dir detection and add logging docs

Previously getLogDir() only checked app.isReady(), which caused
development builds to write logs to the user data directory instead
of the local project logs/ folder. Now uses app.isPackaged to
correctly distinguish production from development environments.

Also adds comprehensive logging system documentation and a debug
utility for verifying Electron environment detection.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main/services/logger/shared.ts

@@ -10,14 +10,19 @@ import { app } from 'electron'
 /**
  * Get log directory path
  * Uses app.getPath('logs') in production, local logs dir in development
+ * Production = app.isPackaged === true
  */
 export function getLogDir(): string {
-  if (app && app.isReady()) {
+  // Check if running in production (packed app)
+  // This must be checked BEFORE app.getPath('logs') because Electron
+  // always returns the user data logs path regardless of environment
+  if (app && app.isReady() && app.isPackaged) {
     return app.getPath('logs')
   }
-  // Fallback for development or before app is ready
-  // Note: synchronous FS calls are acceptable here because this branch only
-  // executes in dev environments when app is not yet ready (rare, at startup).
+
+  // Development environment: use logs directory in project root
+  // Note: synchronous FS calls are acceptable here because this branch
+  // executes in dev environments or before app is ready.
   const devLogDir = path.join(process.cwd(), 'logs')
   if (!fs.existsSync(devLogDir)) {
     fs.mkdirSync(devLogDir, { recursive: true })