fix(codex): add env_key to custom provider + model_catalog_json for picker

- Add env_key = "OPENAI_API_KEY" to [model_providers.custom] in PS1 fallback
  templates (fixes 401 Unauthorized on machines without Python 3.11+)
- Add model_catalog_json config + model_catalog.json file generation
  (fixes empty model picker — all 4 models now visible in interactive mode)
- Both fixes applied in: codex_patcher.py, ucodex_install.ps1, ucodex_update.ps1

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

codex/codex_patcher.py

@@ -44,6 +44,7 @@ RESET = "\033[0m"
 # Managed config keys (we update these, preserve everything else)
 MANAGED_TOP_KEYS = {
     "model", "model_reasoning_effort", "model_provider",
+    "model_catalog_json",
     "approval_policy", "sandbox_mode",
     "check_for_update_on_startup", "forced_login_method",
 }
@@ -163,6 +164,14 @@ def generate_config_toml(existing, config):
     lines.append(f'model = "{config["model"]}"')
     lines.append(f'model_reasoning_effort = "{config.get("model_reasoning_effort", "high")}"')
     lines.append('model_provider = "custom"')
+
+    # Model catalog path (for model picker)
+    codex_dir = os.path.join(os.path.expanduser("~"), ".codex")
+    catalog_path = os.path.join(codex_dir, "model_catalog.json")
+    # Use forward slashes for cross-platform TOML compatibility
+    catalog_path_toml = catalog_path.replace("\\", "/")
+    lines.append(f'model_catalog_json = "{catalog_path_toml}"')
+
     lines.append(f'approval_policy = "{config.get("approval_policy", "never")}"')
     lines.append(f'sandbox_mode = "{config.get("sandbox_mode", "danger-full-access")}"')
     lines.append(f'check_for_update_on_startup = {toml_value(config.get("check_for_update", False))}')
@@ -464,6 +473,21 @@ def apply_all_patches(config, home_dir=None):
     # Backup before any changes
     backup_file(config_path)
 
+    # Generate model catalog JSON for model picker
+    catalog_path = os.path.join(codex_dir, "model_catalog.json")
+    models = config.get("models", [config["model"]])
+    catalog_entries = []
+    for m in models:
+        catalog_entries.append({
+            "id": m,
+            "object": "model",
+            "created": 1700000000,
+            "owned_by": "system"
+        })
+    with open(catalog_path, "w", encoding="utf-8") as f:
+        json.dump(catalog_entries, f, indent=2)
+    print(f"  {'[OK]':>8}  Catalog:    {catalog_path} ({len(models)} models)")
+
     # Generate new config.toml (merge)
     new_content = generate_config_toml(existing, config)
 
@@ -574,6 +598,13 @@ def patch_user(user_home, config):
     existing = read_toml(config_path)
     backup_file(config_path)
 
+    # Generate model catalog
+    catalog_path = os.path.join(codex_dir, "model_catalog.json")
+    models = config.get("models", [config["model"]])
+    catalog_entries = [{"id": m, "object": "model", "created": 1700000000, "owned_by": "system"} for m in models]
+    with open(catalog_path, "w", encoding="utf-8") as f:
+        json.dump(catalog_entries, f, indent=2)
+
     new_content = generate_config_toml(existing, config)
     with open(config_path, "w", encoding="utf-8") as f:
         f.write(new_content)