fix(kanban): resolve hardcoded model display in cards

- Fix model string validation in feature executor
- Remove hardcoded opus 4.5 references
- Update kanban card to show actual selected model
- Clean up completed feature contexts
- Standardize feature list with model/thinking fields

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

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>

app/electron/services/model-provider.js

@@ -206,6 +206,17 @@ class CodexProvider extends ModelProvider {
   async *executeQuery(options) {
     const codexExecutor = require('./codex-executor');
 
+    // Validate that we're not receiving a Claude model string
+    if (options.model && options.model.startsWith('claude-')) {
+      const errorMsg = `Codex provider cannot use Claude model '${options.model}'. Codex only supports OpenAI models (gpt-5.1-codex-max, gpt-5.1-codex, gpt-5.1-codex-mini, gpt-5.1).`;
+      console.error(`[CodexProvider] ${errorMsg}`);
+      yield {
+        type: 'error',
+        error: errorMsg
+      };
+      return;
+    }
+
     const executeOptions = {
       prompt: options.prompt,
       model: options.model,