feat(ai): added OpenCode Zen provider and updated AI model configurations

- Added OpenCode Zen provider with API key-based authentication supporting multiple AI models.
- Added four new free models via OpenCode provider: glm-4.7-free, kimi-k2.5-free, minimax-m2.1-free, and trinity-large-preview-free.
- Added glm-4.7-flash model via Zai provider.
- Updated pricing and configuration for multiple models across Kimi, MiniMax, OpenRouter, Anthropic, Vercel AI Gateway, and Zai providers.
- Removed google/gemini-2.0-flash-exp:free from OpenRouter and stealth models from Vercel AI Gateway.

packages/coding-agent/src/session/auth-storage.ts

@@ -19,6 +19,7 @@ import {
 	loginGitHubCopilot,
 	loginKimi,
 	loginOpenAICodex,
+	loginOpenCode,
 	type OAuthController,
 	type OAuthCredentials,
 	type OAuthProvider,
@@ -782,6 +783,11 @@ export class AuthStorage {
 					ctrl.onProgress ? () => ctrl.onProgress?.("Waiting for browser authentication...") : undefined,
 				);
 				break;
+			case "opencode": {
+				const apiKey = await loginOpenCode(ctrl);
+				credentials = { access: apiKey, refresh: apiKey, expires: Number.MAX_SAFE_INTEGER };
+				break;
+			}
 			default:
 				throw new Error(`Unknown OAuth provider: ${provider}`);
 		}