fix(worker): key rate limiter on peer IP, not forged headers

The rate limiter trusted X-Real-IP, so a client could dodge its limit by
sending a new header value on each request. It must key on the connection
peer address. The key also strips the port, so one client shares one bucket.

internal/worker/ratelimit.go

@@ -2,6 +2,7 @@
 package worker
 
 import (
+	"net"
 	"net/http"
 	"sync"
 	"time"
@@ -206,14 +207,13 @@ func (pcrl *PerClientRateLimiter) Stats() map[string]any {
 }
 
 // PerClientRateLimitMiddleware creates middleware that applies per-client rate limiting.
-// Uses X-Forwarded-For or RemoteAddr to identify clients.
+// Identifies clients by the peer IP of the connection; forwarding headers are spoofable and ignored.
 func PerClientRateLimitMiddleware(limiter *PerClientRateLimiter) func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			// Get client identifier (prefer X-Real-IP from RealIP middleware)
 			clientKey := r.RemoteAddr
-			if xff := r.Header.Get("X-Real-IP"); xff != "" {
-				clientKey = xff
+			if host, _, err := net.SplitHostPort(clientKey); err == nil {
+				clientKey = host
 			}
 
 			if !limiter.Allow(clientKey) {

internal/worker/ratelimit_test.go

@@ -0,0 +1,35 @@
+package worker
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestPerClientRateLimitMiddleware_KeysOnPeerIP(t *testing.T) {
+	h := PerClientRateLimitMiddleware(NewPerClientRateLimiter(0.001, 1))(
+		http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusOK) }))
+
+	do := func(remote, realIP string) int {
+		req := httptest.NewRequest(http.MethodGet, "/", nil)
+		req.RemoteAddr = remote
+		if realIP != "" {
+			req.Header.Set("X-Real-IP", realIP)
+		}
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, req)
+		return rec.Code
+	}
+
+	if got := do("10.0.0.1:1111", "1.1.1.1"); got != http.StatusOK {
+		t.Fatalf("first request: got %d", got)
+	}
+	// Same peer, new port and forged header: must share the exhausted bucket.
+	if got := do("10.0.0.1:2222", "2.2.2.2"); got != http.StatusTooManyRequests {
+		t.Fatalf("spoofed header/new port bypassed limit: got %d", got)
+	}
+	// Different peer is unaffected.
+	if got := do("10.0.0.2:1111", ""); got != http.StatusOK {
+		t.Fatalf("other peer: got %d", got)
+	}
+}

internal/worker/service.go

@@ -1226,7 +1226,7 @@ func (s *Service) setupMiddleware() {
 	// Add gzip compression for responses >1KB (reduces bandwidth ~70% for JSON)
 	s.router.Use(middleware.Compress(5)) // Level 5 = good balance of speed vs compression
 
-	// Apply per-client rate limiting (after RealIP so we get the real client IP)
+	// Apply per-client rate limiting (keyed on the socket peer address; forwarding headers are untrusted)
 	if s.rateLimiter != nil {
 		s.router.Use(PerClientRateLimitMiddleware(s.rateLimiter))
 	}

marketplace.json

@@ -13,7 +13,7 @@
     {
       "name": "claude-mnemonic",
       "description": "Persistent memory system for Claude Code - Go implementation with SQLite and ChromaDB vector search",
-      "version": "0.21.77",
+      "version": "0.21.81",
       "author": {
         "name": "lukaszraczylo",
         "url": "https://github.com/lukaszraczylo"
@@ -23,25 +23,25 @@
       "license": "MIT",
       "homepage": "https://github.com/lukaszraczylo/claude-mnemonic",
       "releases": {
-        "latest": "0.21.77",
+        "latest": "0.21.81",
         "versions": {
-          "0.21.77": {
+          "0.21.81": {
             "releaseDate": "2026-10-03",
             "downloads": {
               "darwin-arm64": {
-                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.77/claude-mnemonic_0.21.77_darwin_arm64.tar.gz",
+                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.81/claude-mnemonic_0.21.81_darwin_arm64.tar.gz",
                 "format": "tar.gz",
-                "sha256": "7bf9c814f4c2d1e9a727c24b0b487bd207dbdc45ed0828aef23e53017f3019d7"
+                "sha256": "8da5803dc0acd44b6e43b4c8d7ff2667811dd8ea5f7bf40643c91829e3e2c37c"
               },
               "linux-amd64": {
-                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.77/claude-mnemonic_0.21.77_linux_amd64.tar.gz",
+                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.81/claude-mnemonic_0.21.81_linux_amd64.tar.gz",
                 "format": "tar.gz",
-                "sha256": "cf5998292c72662b85a25df539a340b8c24e9caa2488fed9fd817d758124eac2"
+                "sha256": "b1a1e7a6317280ef2bce92e349ffdbbf0c9df5cf92f4bce0378c34194b871c01"
               },
               "windows-amd64": {
-                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.77/claude-mnemonic_0.21.77_windows_amd64.zip",
+                "url": "https://github.com/lukaszraczylo/claude-mnemonic/releases/download/v0.21.81/claude-mnemonic_0.21.81_windows_amd64.zip",
                 "format": "zip",
-                "sha256": "762ca4da50188763928802f148ec918e9f02d7678400fe17e46f84d82f5ed57b"
+                "sha256": "869b99958371451a8efe91cc91a9f0eb654a355c0b77a769ab9916e7908c11b1"
               }
             }
           }