feat(proxy-pools): auto-rotate strategy for no-auth providers (#2409)

Add round-robin/random proxy pool rotation for no-auth free providers
(e.g. OpenCode Free) to distribute load across all active pools and
avoid per-IP rate limits. Rotation strategy is selectable per provider
in NoAuthProxyCard and persisted to settings.providerStrategies.

src/shared/components/NoAuthProxyCard.js

@@ -1,16 +1,22 @@
 "use client";
 
-import { useEffect, useState } from "react";
+import { useCallback, useEffect, useState } from "react";
 import PropTypes from "prop-types";
 import Card from "./Card";
 import Select from "./Select";
 import Badge from "./Badge";
 
 const NONE_PROXY_POOL_VALUE = "__none__";
+const STRATEGIES = [
+  { value: "none", label: "None (single pool)" },
+  { value: "round-robin", label: "Round-robin" },
+  { value: "random", label: "Random" },
+];
 
 export default function NoAuthProxyCard({ providerId }) {
   const [proxyPools, setProxyPools] = useState([]);
   const [proxyPoolId, setProxyPoolId] = useState(NONE_PROXY_POOL_VALUE);
+  const [rotateStrategy, setRotateStrategy] = useState("none");
   const [saving, setSaving] = useState(false);
   const [savedFlash, setSavedFlash] = useState(false);
 
@@ -24,20 +30,22 @@ export default function NoAuthProxyCard({ providerId }) {
       setProxyPools(poolData.proxyPools || []);
       const override = (settingsData.providerStrategies || {})[providerId] || {};
       setProxyPoolId(override.proxyPoolId || NONE_PROXY_POOL_VALUE);
+      setRotateStrategy(override.rotateStrategy || "none");
     }).catch(() => {});
     return () => { cancelled = true; };
   }, [providerId]);
 
-  const handleChange = async (newValue) => {
-    setProxyPoolId(newValue);
+  const save = useCallback(async (poolId, strategy) => {
     setSaving(true);
     try {
       const res = await fetch("/api/settings", { cache: "no-store" });
       const data = res.ok ? await res.json() : {};
       const current = data.providerStrategies || {};
       const override = { ...(current[providerId] || {}) };
-      if (newValue === NONE_PROXY_POOL_VALUE) delete override.proxyPoolId;
-      else override.proxyPoolId = newValue;
+      if (poolId === NONE_PROXY_POOL_VALUE) delete override.proxyPoolId;
+      else override.proxyPoolId = poolId;
+      if (strategy === "none") delete override.rotateStrategy;
+      else override.rotateStrategy = strategy;
       const updated = { ...current };
       if (Object.keys(override).length === 0) delete updated[providerId];
       else updated[providerId] = override;
@@ -49,12 +57,25 @@ export default function NoAuthProxyCard({ providerId }) {
       setSavedFlash(true);
       setTimeout(() => setSavedFlash(false), 1500);
     } catch (e) {
-      console.log("Save proxyPoolId error:", e);
+      console.log("Save proxy config error:", e);
     } finally {
       setSaving(false);
     }
+  }, [providerId]);
+
+  const handlePoolChange = (newPoolId) => {
+    setProxyPoolId(newPoolId);
+    save(newPoolId, rotateStrategy);
   };
 
+  const handleStrategyChange = (newStrategy) => {
+    setRotateStrategy(newStrategy);
+    save(proxyPoolId, newStrategy);
+  };
+
+  const canRotate = proxyPools.length >= 2;
+  const isRotation = rotateStrategy !== "none";
+
   return (
     <Card>
       <div className="flex items-center gap-3 mb-4">
@@ -67,16 +88,43 @@ export default function NoAuthProxyCard({ providerId }) {
         </div>
         {savedFlash && <Badge variant="success" size="sm">Saved</Badge>}
       </div>
+
       <Select
         label="Proxy Pool"
         value={proxyPoolId}
-        onChange={(e) => handleChange(e.target.value)}
-        disabled={saving}
+        onChange={(e) => handlePoolChange(e.target.value)}
+        disabled={saving || isRotation}
         options={[
           { value: NONE_PROXY_POOL_VALUE, label: "None (direct)" },
           ...proxyPools.map((pool) => ({ value: pool.id, label: pool.name })),
         ]}
+        hint={isRotation ? "Pool selector is ignored when rotation is active — all active pools are used." : undefined}
       />
+
+      <div className="flex flex-col gap-2 mt-4">
+        <label className="text-sm font-medium text-text-main">Rotation Strategy</label>
+        <select
+          value={rotateStrategy}
+          onChange={(e) => handleStrategyChange(e.target.value)}
+          disabled={saving}
+          className="py-2 px-3 text-sm text-text-main bg-white dark:bg-white/5 border border-black/10 dark:border-white/10 rounded-md focus:ring-1 focus:ring-primary/30 focus:border-primary/50 focus:outline-none transition-all disabled:opacity-50"
+        >
+          {STRATEGIES.map((s) => (
+            <option key={s.value} value={s.value} disabled={s.value !== "none" && !canRotate}>
+              {s.label}
+            </option>
+          ))}
+        </select>
+        <p className="text-xs text-text-muted">
+          {!canRotate
+            ? `Need at least 2 active proxy pools for rotation.`
+            : isRotation
+              ? rotateStrategy === "round-robin"
+                ? `Rotating through all ${proxyPools.length} active pools in order. State is in-memory (resets on restart).`
+                : `Picking a random pool from ${proxyPools.length} active pools each request.`
+              : `Uses the selected pool above. Set to Round-robin or Random to rotate across all active pools.`}
+        </p>
+      </div>
     </Card>
   );
 }