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.

src/app/api/models/custom/route.js

@@ -0,0 +1,48 @@
+import { NextResponse } from "next/server";
+import { getCustomModels, addCustomModel, deleteCustomModel } from "@/models";
+
+export const dynamic = "force-dynamic";
+
+// GET /api/models/custom - List all custom models
+export async function GET() {
+  try {
+    const models = await getCustomModels();
+    return NextResponse.json({ models });
+  } catch (error) {
+    console.log("Error fetching custom models:", error);
+    return NextResponse.json({ error: "Failed to fetch custom models" }, { status: 500 });
+  }
+}
+
+// POST /api/models/custom - Add custom model
+export async function POST(request) {
+  try {
+    const { providerAlias, id, type, name } = await request.json();
+    if (!providerAlias || !id) {
+      return NextResponse.json({ error: "providerAlias and id required" }, { status: 400 });
+    }
+    const added = await addCustomModel({ providerAlias, id, type: type || "llm", name });
+    return NextResponse.json({ success: true, added });
+  } catch (error) {
+    console.log("Error adding custom model:", error);
+    return NextResponse.json({ error: "Failed to add custom model" }, { status: 500 });
+  }
+}
+
+// DELETE /api/models/custom?providerAlias=xxx&id=yyy&type=zzz
+export async function DELETE(request) {
+  try {
+    const { searchParams } = new URL(request.url);
+    const providerAlias = searchParams.get("providerAlias");
+    const id = searchParams.get("id");
+    const type = searchParams.get("type") || "llm";
+    if (!providerAlias || !id) {
+      return NextResponse.json({ error: "providerAlias and id required" }, { status: 400 });
+    }
+    await deleteCustomModel({ providerAlias, id, type });
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.log("Error deleting custom model:", error);
+    return NextResponse.json({ error: "Failed to delete custom model" }, { status: 500 });
+  }
+}

src/app/api/v1/images/generations/route.js

@@ -0,0 +1,16 @@
+import { handleImageGeneration } from "@/sse/handlers/imageGeneration.js";
+
+export async function OPTIONS() {
+  return new Response(null, {
+    headers: {
+      "Access-Control-Allow-Origin": "*",
+      "Access-Control-Allow-Methods": "POST, OPTIONS",
+      "Access-Control-Allow-Headers": "*",
+    },
+  });
+}
+
+/** POST /v1/images/generations - OpenAI-compatible image generation endpoint */
+export async function POST(request) {
+  return await handleImageGeneration(request);
+}