feat: align z.ai headers with OpenClaw, enable OpenRouter caching

- z.ai now sends 3 exact OpenRouter attribution headers matching
  OpenClaw's source (HTTP-Referer, X-OpenRouter-Title, X-OpenRouter-Categories)
  with full category list for maximum free-tier eligibility
- openrouter.ai requests include X-OpenRouter-Cache: true header
  to leverage OpenRouter's response caching and reduce latency/cost

src/translate-proxy.py

@@ -1290,6 +1290,27 @@ def forwarded_headers(request_headers, extra=None, browser_ua=False):
         headers.update(extra)
     return headers
 
+
+def _openrouter_extra():
+    if not TARGET_URL:
+        return {}
+    if "z.ai" in TARGET_URL:
+        return {
+            "HTTP-Referer": "https://openclaw.ai",
+            "X-OpenRouter-Title": "OpenClaw",
+            "X-OpenRouter-Categories":
+                "cli-agent,cloud-agent,programming-app,creative-writing,"
+                "writing-assistant,general-chat,personal-agent",
+        }
+    if "openrouter.ai" in TARGET_URL:
+        return {
+            "HTTP-Referer": "https://chats-llm.com",
+            "X-OpenRouter-Title": "Chats-LLM",
+            "X-OpenRouter-Categories": "general-chat, ide-extension",
+            "X-OpenRouter-Cache": "true",
+        }
+    return {}
+
 _MAX_INPUT_ITEMS = 30
 _MAX_TOOL_OUTPUT_CHARS = 8000
 _COMPACT_KEEP_RECENT = 10
@@ -4321,6 +4342,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
             fwd = forwarded_headers(self.headers, {
                 "Content-Type": "application/json",
                 "Authorization": f"Bearer {effective_key}",
+                **_openrouter_extra(),
             }, browser_ua=True)
             print(f"[{self._session_id}] POST {target} model={model} stream={stream} items={len(input_data) if isinstance(input_data,list) else 1}", file=sys.stderr)
             chat_body_b = json.dumps(chat_body).encode()
@@ -4947,6 +4969,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
             fwd = forwarded_headers(self.headers, {
                 "Content-Type": "application/json",
                 "Authorization": f"Bearer {r_key}",
+                **_openrouter_extra(),
             }, browser_ua=True)
             print(f"[{self._session_id}] trying route '{route.get('name', r_url)}' model={r_model}", file=sys.stderr)
             req = urllib.request.Request(target, data=json.dumps(chat_body).encode(), headers=fwd)
@@ -5209,6 +5232,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
                 "Content-Type": "application/json",
                 "x-api-key": API_KEY,
                 "anthropic-version": "2023-06-01",
+                **_openrouter_extra(),
             }),
         )
         self._forward(req, stream, model,
@@ -5276,7 +5300,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
                 "threadId": thread_id,
             }
 
-            fwd = forwarded_headers(self.headers, headers_extra, browser_ua=True)
+            fwd = forwarded_headers(self.headers, {**headers_extra, **_openrouter_extra()}, browser_ua=True)
             print(f"[{self._session_id}] POST {target} model={model} stream={stream} attempt={attempt} [command-code]", file=sys.stderr)
             req = urllib.request.Request(
                 target,
@@ -5810,7 +5834,7 @@ class Handler(http.server.BaseHTTPRequestHandler):
                     req_body["reasoning_effort"] = REASONING_EFFORT
 
             req_body_b = json.dumps(req_body).encode()
-            fwd = forwarded_headers(self.headers, headers_extra, browser_ua=True)
+            fwd = forwarded_headers(self.headers, {**headers_extra, **_openrouter_extra()}, browser_ua=True)
             print(f"[auto-sense] POST {target} model={model} attempt={attempt} schema={schema.hints()}", file=sys.stderr)
 
             req = urllib.request.Request(target, data=req_body_b, headers=fwd)