Feature/lmstudio provider (#30)

* chore: just a plan update

* Add LM Studio as local AI provider (OpenAI-compatible, like Ollama)

* Convert WebP thumbnails to JPEG before image analysis for LM Studio compatibility

* Strengthen language enforcement in image analysis prompt for local models

* Use i18n localized prompts for image analysis instead of English instructions

* Add airplane mode (Flugmodus) with status bar toggle and offline model preferences

* Fix flightmode: persist model IDs, skip network when offline, airplane icon

* Auto-fallback to offline models in airplane mode for chat, title, and image analysis

* Auto-select first local model as offline fallback when no explicit offline model configured

* Block git fetch/pull/push and site upload in airplane mode

* fix: thumbnails optimized for AI

* fix: error handling in airplane mode

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Co-authored-by: hugo <hugoms@me.com>

src/main/engine/GitEngine.ts

@@ -129,7 +129,7 @@ export interface GitLfsPruneResult {
 
 export interface GitActionResult {
   success: boolean;
-  code?: 'auth-required' | 'conflict' | 'network' | 'action-failed';
+  code?: 'auth-required' | 'conflict' | 'network' | 'action-failed' | 'offline';
   error?: string;
   guidance?: string[];
 }