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.

src/app/api/proxy-pools/fitness/clear-all/route.js

@@ -0,0 +1,22 @@
+import { NextResponse } from "next/server";
+import { clearAllPoolUnfit } from "open-sse/services/proxyPoolFitness.js";
+
+// POST /api/proxy-pools/fitness/clear-all
+// Body: { provider?: string } — clears every mark, or only marks scoped to the
+// given provider ("provider::*") when provided.
+export async function POST(request) {
+  try {
+    let body = {};
+    try {
+      body = await request.json();
+    } catch {
+      body = {};
+    }
+    const provider = typeof body?.provider === "string" && body.provider.trim() ? body.provider.trim() : null;
+    clearAllPoolUnfit(provider);
+    return NextResponse.json({ ok: true, provider: provider || null });
+  } catch (error) {
+    console.log("Error clearing proxy fitness:", error);
+    return NextResponse.json({ error: "Failed to clear proxy fitness" }, { status: 500 });
+  }
+}