fix: address GitHub issues #511, #517, #527, #531

- #511: Add gemini-3-flash model to GeminiAgent (type, RPM limits, validation)
- #517: Replace PowerShell with WMIC for Windows process management (fixes Git Bash/WSL)
- #527: Add Apple Silicon Homebrew paths for bun and uv detection
- #531: Remove duplicate type definitions from export-memories.ts using bridge file

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/services/worker/GeminiAgent.ts

@@ -36,7 +36,8 @@ export type GeminiModel =
   | 'gemini-2.5-flash'
   | 'gemini-2.5-pro'
   | 'gemini-2.0-flash'
-  | 'gemini-2.0-flash-lite';
+  | 'gemini-2.0-flash-lite'
+  | 'gemini-3-flash';
 
 // Free tier RPM limits by model (requests per minute)
 const GEMINI_RPM_LIMITS: Record<GeminiModel, number> = {
@@ -45,6 +46,7 @@ const GEMINI_RPM_LIMITS: Record<GeminiModel, number> = {
   'gemini-2.5-pro': 5,
   'gemini-2.0-flash': 15,
   'gemini-2.0-flash-lite': 30,
+  'gemini-3-flash': 5,
 };
 
 // Track last request time for rate limiting
@@ -373,6 +375,7 @@ export class GeminiAgent {
       'gemini-2.5-pro',
       'gemini-2.0-flash',
       'gemini-2.0-flash-lite',
+      'gemini-3-flash',
     ];
 
     let model: GeminiModel;