feat: add missing Codex models and restore subprocess logs

- Added gpt-5.1-codex-mini model (lightweight, faster)
- Added gpt-5.1 model (general-purpose)
- Restored subprocess spawn/exit logs for debugging
- Now all 5 Codex models are available:
  * GPT-5.2
  * GPT-5.1 Codex Max
  * GPT-5.1 Codex
  * GPT-5.1 Codex Mini
  * GPT-5.1

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

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

apps/server/src/providers/codex-provider.ts

@@ -537,6 +537,30 @@ export class CodexProvider extends BaseProvider {
         supportsTools: true,
         tier: "standard",
       },
+      {
+        id: "gpt-5.1-codex-mini",
+        name: "GPT-5.1 Codex Mini",
+        modelString: "gpt-5.1-codex-mini",
+        provider: "openai-codex",
+        description: "Faster, lightweight Codex model",
+        contextWindow: 256000,
+        maxOutputTokens: 16384,
+        supportsVision: false,
+        supportsTools: true,
+        tier: "basic",
+      },
+      {
+        id: "gpt-5.1",
+        name: "GPT-5.1",
+        modelString: "gpt-5.1",
+        provider: "openai-codex",
+        description: "General-purpose GPT-5.1 model",
+        contextWindow: 256000,
+        maxOutputTokens: 32768,
+        supportsVision: true,
+        supportsTools: true,
+        tier: "standard",
+      },
     ];
   }