fix(opencode): allow partial command overrides in JSON config

packages/opencode/src/command/index.ts

@@ -95,14 +95,15 @@ export const layer = Layer.effect(
       }
 
       for (const [name, command] of Object.entries(cfg.command ?? {})) {
+        if (!command.template) continue
         commands[name] = {
           name,
           agent: command.agent,
           model: command.model,
           description: command.description,
           source: "command",
           get template() {
-            return command.template
+            return command.template!
           },
           subtask: command.subtask,
           hints: hints(command.template),

packages/opencode/src/config/command.ts

@@ -13,7 +13,7 @@ import { ConfigModelID } from "./model-id"
 const log = Log.create({ service: "config" })
 
 export const Info = Schema.Struct({
-  template: Schema.String,
+  template: Schema.optional(Schema.String),
   description: Schema.optional(Schema.String),
   agent: Schema.optional(Schema.String),
   model: Schema.optional(ConfigModelID),

packages/opencode/test/config/config.test.ts

@@ -727,6 +727,30 @@ test("handles command configuration", async () => {
   })
 })
 
+test("accepts partial command override without template", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await writeConfig(dir, {
+        $schema: "https://opencode.ai/config.json",
+        command: {
+          commit: {
+            model: "anthropic/claude-4-6-sonnet",
+          },
+        },
+      })
+    },
+  })
+  await WithInstance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const config = await load()
+      expect(config.command?.["commit"]).toEqual({
+        model: "anthropic/claude-4-6-sonnet",
+      })
+    },
+  })
+})
+
 test("migrates autoshare to share field", async () => {
   await using tmp = await tmpdir({
     init: async (dir) => {