Add API tokens management, docs & UI

Introduce full API token support: add a Prisma migration to create api_tokens table and indexes; add types, constants and a generateApiToken utility (hashed token + prefix). Update admin and user token routes to use the generator, enforce per-user active token caps, and integrate rate-limit checks. Add an interactive API docs page with TokenInput, EndpointCard and ResponseViewer components, plus a protected page route. Improve confirmation UX with an accessible ConfirmDialog (focus trap, Escape to close, animations) and wire confirm flows into admin/profile token sections; also update ConfirmModal to accept node messages. Add dialog CSS animations and enhance clipboard error handling. Update related middleware, utils and tests to reflect changes.

src/lib/utils/apiTokenRateLimit.ts

@@ -1,3 +1,11 @@
+/**
+ * Component: API Token Rate Limiting
+ * Documentation: documentation/backend/services/api-tokens.md
+ *
+ * In-memory sliding-window rate limiter with lazy eviction and periodic sweep
+ * to prevent unbounded memory growth.
+ */
+
 type Bucket = {
   count: number;
   resetAt: number;
@@ -10,11 +18,42 @@ type RateLimitResult = {
 
 const buckets = new Map<string, Bucket>();
 
+/** Number of checkRateLimit calls since the last full sweep */
+let checkCount = 0;
+
+/** How often (in calls) to perform a full sweep of expired buckets */
+const SWEEP_INTERVAL = 100;
+
+/**
+ * Sweep the entire bucket map and delete all expired entries.
+ * Called automatically every SWEEP_INTERVAL checks.
+ */
+function sweepExpiredBuckets(): void {
+  const now = Date.now();
+  for (const [key, bucket] of buckets) {
+    if (now >= bucket.resetAt) {
+      buckets.delete(key);
+    }
+  }
+}
+
 function checkRateLimit(key: string, maxRequests: number, windowMs: number): RateLimitResult {
   const now = Date.now();
+
+  // Periodic full sweep every SWEEP_INTERVAL calls
+  checkCount += 1;
+  if (checkCount >= SWEEP_INTERVAL) {
+    checkCount = 0;
+    sweepExpiredBuckets();
+  }
+
   const current = buckets.get(key);
 
+  // Lazy eviction: if the bucket is expired, delete it and start fresh
   if (!current || now >= current.resetAt) {
+    if (current) {
+      buckets.delete(key);
+    }
     buckets.set(key, { count: 1, resetAt: now + windowMs });
     return { allowed: true, retryAfterSeconds: Math.ceil(windowMs / 1000) };
   }
@@ -40,3 +79,14 @@ export function checkApiTokenCreateRateLimit(actorId: string): RateLimitResult {
 export function checkApiTokenRevokeRateLimit(actorId: string): RateLimitResult {
   return checkRateLimit(`api-token-revoke:${actorId}`, 20, 60 * 1000);
 }
+
+/** Reset all buckets and the sweep counter. For testing only. */
+export function _resetBuckets(): void {
+  buckets.clear();
+  checkCount = 0;
+}
+
+/** Get the current number of tracked buckets. For testing only. */
+export function _getBucketCount(): number {
+  return buckets.size;
+}