refactor(search): fold zai-search into the glm provider

The separate zai-search entry showed "No connections" on the web search
page because credentials live on the `glm` connection, not on it. Every
other provider that does both chat and search (antigravity, kimi, xai,
gemini) declares webSearch on the provider itself, so do the same here.

- glm gains serviceKinds ["llm", "webSearch"] and the MCP searchConfig
- the request builder / normalizer move from "zai-search" to "glm"
- drop the zai-search registry entry and its svg logo, which also
  removes the only need for svg logo support in getProviderIconSrc

ollama-search keeps its own entry and credentialFallback: its search
endpoint is unrelated to the ollama chat transport.

open-sse/providers/registry/glm.js

@@ -53,6 +53,20 @@ export default {
     { id: "glm-4.7", name: "GLM 4.7" },
     { id: "glm-4.6v", name: "GLM 4.6V (Vision)" },
   ],
+  serviceKinds: ["llm", "webSearch"],
+  // Coding plan bundles web search on the same API key as chat.
+  searchConfig: {
+    baseUrl: "https://api.z.ai/api/mcp/web_search_prime/mcp",
+    method: "POST",
+    authType: "apikey",
+    authHeader: "bearer",
+    costPerQuery: 0,
+    searchTypes: ["web"],
+    defaultMaxResults: 5,
+    maxMaxResults: 50,
+    timeoutMs: 10000,
+    cacheTTLMs: 300000,
+  },
   features: {
     usage: true,
     usageApikey: true,