feat(auth): add anthropic api key storage and cli auth

src/daemon/models.ts

@@ -3,6 +3,7 @@ import { AnthropicClient, OpenAIClient, OllamaClient, LlamaCppClient, GeminiClie
 import type { ModelClient, RetryConfig, ModelTier } from '../models/index.js';
 import { logger } from '../logger.js';
 import { getZaiApiKey } from '../auth/zai.js';
+import { getAnthropicApiKey } from '../auth/anthropic.js';
 
 /**
  * Resolve an API key from config or environment variable.
@@ -44,9 +45,15 @@ function resolveAuthCredential(cfg: ModelConfig, apiKeyEnvVar: string, authToken
 export function createClientFromConfig(cfg: ModelConfig): ModelClient {
   switch (cfg.provider) {
     case 'anthropic':
+      if (!cfg.api_key && !getAnthropicApiKey()) {
+        throw new Error(
+          'Anthropic API key not configured. ' +
+          'Set ANTHROPIC_API_KEY, run `flynn anthropic-auth`, or provide api_key in config.',
+        );
+      }
       return new AnthropicClient({
         model: cfg.model,
-        apiKey: cfg.api_key,
+        apiKey: cfg.api_key ?? getAnthropicApiKey() ?? undefined,
         authToken: cfg.auth_token,
       });
     case 'openai':