feat(api): tiered cumulative quota + self-service registration

Anonymous callers get a free cumulative quota (1000 calls per IP); once
exhausted they get 403 quota_exhausted and must register. Public users can
self-register (email+password) to obtain a higher-quota API key, view usage,
and regenerate the key. Quota counters live in Redis; the public API stays
read-only except for the registration writes.

- migration 0011: app_user table + api_key.quota_total + 'registered' tier
- ratelimit: IncrTotal/TotalUsed/CopyTotal lifetime counters
- middleware: enforce cumulative quota + X-Quota-* headers
- store: RegisterUser/Authenticate/RegenerateKey (bcrypt)
- handlers: POST /api/v1/register, /account, /account/regenerate
- admin: quota_total column + registered tier
- public: 'API 密钥' account page + API docs quota section

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

admin-frontend/src/components/ApiKeysPage.tsx

@@ -4,9 +4,10 @@ import type { ApiKey } from "../types";
 import { Copy, KeyRound, Plus, Trash2 } from "lucide-react";
 
 const TIERS = [
-  { key: "free", label: "免费 (free)", rate: 120 },
-  { key: "partner", label: "合作方 (partner)", rate: 600 },
-  { key: "internal", label: "内部 (internal)", rate: 6000 },
+  { key: "free", label: "免费 (free)", rate: 120, quota: 1000 },
+  { key: "registered", label: "注册用户 (registered)", rate: 300, quota: 100000 },
+  { key: "partner", label: "合作方 (partner)", rate: 600, quota: 0 },
+  { key: "internal", label: "内部 (internal)", rate: 6000, quota: 0 },
 ];
 
 function tierLabel(tier: string): string {
@@ -111,6 +112,7 @@ export default function ApiKeysPage() {
               <th className="px-4 py-2 font-medium">级别</th>
               <th className="px-4 py-2 font-medium">速率/分钟</th>
               <th className="px-4 py-2 font-medium">用量(今日/累计)</th>
+              <th className="px-4 py-2 font-medium">累计配额</th>
               <th className="px-4 py-2 font-medium">状态</th>
               <th className="px-4 py-2 font-medium"></th>
             </tr>
@@ -118,7 +120,7 @@ export default function ApiKeysPage() {
           <tbody className="divide-y">
             {rows.length === 0 ? (
               <tr>
-                <td colSpan={7} className="px-4 py-8 text-center text-gray-400">
+                <td colSpan={8} className="px-4 py-8 text-center text-gray-400">
                   暂无密钥
                 </td>
               </tr>
@@ -139,6 +141,15 @@ export default function ApiKeysPage() {
                   <td className="px-4 py-2 text-gray-600">
                     {k.usage.today} / {k.usage.total}
                   </td>
+                  <td className="px-4 py-2 text-gray-600">
+                    {k.quota_total > 0 ? (
+                      <span className={k.usage.total >= k.quota_total ? "text-red-600" : ""}>
+                        {k.usage.total.toLocaleString()} / {k.quota_total.toLocaleString()}
+                      </span>
+                    ) : (
+                      <span className="text-gray-400">不限</span>
+                    )}
+                  </td>
                   <td className="px-4 py-2">
                     {k.revoked_at ? (
                       <span className="text-xs rounded px-2 py-0.5 bg-red-50 text-red-700">
@@ -182,13 +193,17 @@ function CreateKeyForm({
   const [ownerEmail, setOwnerEmail] = useState("");
   const [tier, setTier] = useState("free");
   const [rate, setRate] = useState(120);
+  const [quota, setQuota] = useState(1000);
   const [busy, setBusy] = useState(false);
   const [error, setError] = useState("");
 
   function pickTier(t: string) {
     setTier(t);
     const def = TIERS.find((x) => x.key === t);
-    if (def) setRate(def.rate);
+    if (def) {
+      setRate(def.rate);
+      setQuota(def.quota);
+    }
   }
 
   async function submit() {
@@ -204,6 +219,7 @@ function CreateKeyForm({
         owner_email: ownerEmail.trim() || undefined,
         tier,
         rate_limit_per_min: rate,
+        quota_total: quota,
       });
       onCreated(res.key);
     } catch (e) {
@@ -260,6 +276,16 @@ function CreateKeyForm({
             onChange={(e) => setRate(Math.max(1, parseInt(e.target.value || "1", 10)))}
           />
         </label>
+        <label className="block">
+          <span className="text-xs text-gray-500">累计配额（总调用次数，0=不限）</span>
+          <input
+            type="number"
+            min={0}
+            className="w-full border rounded-md px-3 py-2 text-sm mt-1"
+            value={quota}
+            onChange={(e) => setQuota(Math.max(0, parseInt(e.target.value || "0", 10)))}
+          />
+        </label>
       </div>
       <div className="mt-4 flex gap-2">
         <button