feat: add OpenCode Go provider and support for custom models

- Introduced OpenCode Go provider with relevant configurations.
- Enhanced model management by allowing users to add and delete custom models.
- Updated UI components to support model selection for image types.
- Adjusted sidebar visibility to include image media kinds.

open-sse/executors/index.js

@@ -9,6 +9,7 @@ import { CursorExecutor } from "./cursor.js";
 import { VertexExecutor } from "./vertex.js";
 import { QwenExecutor } from "./qwen.js";
 import { OpenCodeExecutor } from "./opencode.js";
+import { OpenCodeGoExecutor } from "./opencode-go.js";
 import { GrokWebExecutor } from "./grok-web.js";
 import { PerplexityWebExecutor } from "./perplexity-web.js";
 import { DefaultExecutor } from "./default.js";
@@ -27,6 +28,7 @@ const executors = {
   "vertex-partner": new VertexExecutor("vertex-partner"),
   qwen: new QwenExecutor(),
   opencode: new OpenCodeExecutor(),
+  "opencode-go": new OpenCodeGoExecutor(),
   "grok-web": new GrokWebExecutor(),
   "perplexity-web": new PerplexityWebExecutor(),
 };
@@ -56,5 +58,6 @@ export { VertexExecutor } from "./vertex.js";
 export { DefaultExecutor } from "./default.js";
 export { QwenExecutor } from "./qwen.js";
 export { OpenCodeExecutor } from "./opencode.js";
+export { OpenCodeGoExecutor } from "./opencode-go.js";
 export { GrokWebExecutor } from "./grok-web.js";
 export { PerplexityWebExecutor } from "./perplexity-web.js";

open-sse/executors/opencode-go.js

@@ -0,0 +1,51 @@
+import { BaseExecutor } from "./base.js";
+import { PROVIDERS } from "../config/providers.js";
+
+// Models that use /zen/go/v1/messages (Anthropic/Claude format + x-api-key auth)
+const CLAUDE_FORMAT_MODELS = new Set(["minimax-m2.5", "minimax-m2.7"]);
+
+const BASE = "https://opencode.ai/zen/go/v1";
+
+// Kimi (Moonshot) requires reasoning_content on assistant tool_call messages when thinking is on.
+// OpenAI-format clients don't send it -> upstream 400. Inject a non-empty placeholder.
+const KIMI_REASONING_PLACEHOLDER = " ";
+
+export class OpenCodeGoExecutor extends BaseExecutor {
+  constructor() {
+    super("opencode-go", PROVIDERS["opencode-go"]);
+  }
+
+  // buildUrl runs before buildHeaders in BaseExecutor.execute, cache model here
+  buildUrl(model) {
+    this._lastModel = model;
+    return CLAUDE_FORMAT_MODELS.has(model)
+      ? `${BASE}/messages`
+      : `${BASE}/chat/completions`;
+  }
+
+  buildHeaders(credentials, stream = true) {
+    const key = credentials?.apiKey || credentials?.accessToken;
+    const headers = { "Content-Type": "application/json" };
+
+    if (CLAUDE_FORMAT_MODELS.has(this._lastModel)) {
+      headers["x-api-key"] = key;
+      headers["anthropic-version"] = "2023-06-01";
+    } else {
+      headers["Authorization"] = `Bearer ${key}`;
+    }
+
+    if (stream) headers["Accept"] = "text/event-stream";
+    return headers;
+  }
+
+  transformRequest(model, body) {
+    if (!model?.startsWith?.("kimi-") || !body?.messages) return body;
+    const messages = body.messages.map(m => {
+      if (m?.role === "assistant" && Array.isArray(m.tool_calls) && !("reasoning_content" in m)) {
+        return { ...m, reasoning_content: KIMI_REASONING_PLACEHOLDER };
+      }
+      return m;
+    });
+    return { ...body, messages };
+  }
+}