Refactor: Update git-committer model to Gemini Flash Lite Preview

This change updates the model used by the git-committer agent configuration to google/gemini-2.5-flash-lite-preview-09-2025.

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Co-Authored-By: Codebuff <noreply@codebuff.com>

Author: brandonkachen

.agents/git-committer.ts

@@ -8,7 +8,7 @@ import type {
 const definition: AgentDefinition = {
   id: 'git-committer',
   displayName: 'Mitt the Git Committer',
-  model: 'openai/gpt-5-nano',
+  model: 'google/gemini-2.5-flash-lite-preview-09-2025',
 
   publisher,
   toolNames: ['read_files', 'run_terminal_command', 'add_message', 'end_turn'],