fix(llm): checkHealth uses key presence check, not live API call

Live Anthropic API call during health check causes 429 when the pipeline
is actively running, blocking all subsequent regenerate requests.

packages/api/src/llm/client.ts

@@ -282,26 +282,8 @@ export async function chat(
 /** Check if configured LLM provider is available */
 export async function checkHealth(): Promise<{ ok: boolean; model: string; provider: string; error?: string }> {
   if (BLOG_LLM_PROVIDER === "anthropic" && ANTHROPIC_API_KEY) {
-    try {
-      // Quick validation — just check API key works
-      const resp = await fetch("https://api.anthropic.com/v1/messages", {
-        method: "POST",
-        headers: {
-          "Content-Type": "application/json",
-          "x-api-key": ANTHROPIC_API_KEY,
-          "anthropic-version": "2023-06-01",
-        },
-        body: JSON.stringify({
-          model: ANTHROPIC_MODEL,
-          max_tokens: 5,
-          messages: [{ role: "user", content: "hi" }],
-        }),
-        signal: AbortSignal.timeout(10000),
-      });
-      return { ok: resp.ok, model: ANTHROPIC_MODEL, provider: "anthropic" };
-    } catch (err) {
-      return { ok: false, model: ANTHROPIC_MODEL, provider: "anthropic", error: (err as Error).message };
-    }
+    // Key presence check only — live API call causes 429 when pipeline is running
+    return { ok: true, model: ANTHROPIC_MODEL, provider: "anthropic" };
   }
 
   try {