feat(proxy-fitness): pool fitness registry + Smart rotation + pool-scoped retry

Pool/IP fitness registry (globalThis-backed, provider::model scopes, 5-min
cooldown, provider::* wildcard) fed by pool-scoped failures: freebuff
limited-IP / model-locked gates and opencode free per-IP limits. chatCore
retries a failed pool via another pool without locking the account; new
Smart rotation strategy (per-connection + no-auth providers) skips unfit
pools. Proxy Fitness dashboard page: active-block table with provider/IP
filters, per-record Clear and provider-scoped Clear All; egress column via
pool geo enrichment. Unit tests for the registry.

open-sse/executors/opencode.js

@@ -5,6 +5,12 @@ import { injectReasoningContent } from "../utils/reasoningContentInjector.js";
 // Models that use /zen/v1/messages (claude format)
 const MESSAGES_MODELS = new Set();
 
+// OpenCode free tier is limited per egress IP — a 429/403 with a limit-ish
+// body means the POOL's IP is exhausted, not the account. Declare it
+// pool-scoped so chatCore marks the pool unfit, retries via another pool, and
+// it shows up (clearable) on the Proxy Fitness page.
+const IP_LIMIT_BODY = /limit|rate|quota|exhausted|capacity|too many|retry/i;
+
 export class OpenCodeExecutor extends BaseExecutor {
   constructor() {
     super("opencode", PROVIDERS.opencode);
@@ -29,4 +35,17 @@ export class OpenCodeExecutor extends BaseExecutor {
       "Accept": "text/event-stream"
     };
   }
+
+  parseError(response, bodyText) {
+    const status = response?.status || 0;
+    const text = String(bodyText || "");
+    if ((status === 429 || status === 403) && IP_LIMIT_BODY.test(text)) {
+      return {
+        status,
+        message: text.slice(0, 300) || `OpenCode free limit (${status})`,
+        poolScoped: { reason: "ip-limit" },
+      };
+    }
+    return null; // fall through to default parsing
+  }
 }