fix(command-loader): preserve model field for opencode commands only

- Claude Code commands (user, project scope): sanitize model to undefined
- OpenCode commands (opencode, opencode-project scope): preserve model as-is

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

Author: code-yeongyu

src/features/claude-code-command-loader/loader.ts

@@ -34,12 +34,13 @@ $ARGUMENTS
 
       const formattedDescription = `(${scope}) ${data.description || ""}`
 
+      const isOpencodeSource = scope === "opencode" || scope === "opencode-project"
       const definition: CommandDefinition = {
         name: commandName,
         description: formattedDescription,
         template: wrappedTemplate,
         agent: data.agent,
-        model: sanitizeModelField(data.model),
+        model: sanitizeModelField(data.model, isOpencodeSource ? "opencode" : "claude-code"),
         subtask: data.subtask,
         argumentHint: data["argument-hint"],
       }

src/shared/model-sanitizer.ts

@@ -1,13 +1,12 @@
-/**
- * Sanitizes model field from frontmatter.
- * Always returns undefined to let SDK use default model.
- *
- * Claude Code and OpenCode use different model ID formats,
- * so we ignore the model field and let OpenCode use its configured default.
- *
- * @param _model - Raw model value from frontmatter (ignored)
- * @returns Always undefined to inherit default model
- */
-export function sanitizeModelField(_model: unknown): undefined {
+type CommandSource = "claude-code" | "opencode"
+
+export function sanitizeModelField(model: unknown, source: CommandSource = "claude-code"): string | undefined {
+  if (source === "claude-code") {
+    return undefined
+  }
+  
+  if (typeof model === "string" && model.trim().length > 0) {
+    return model.trim()
+  }
   return undefined
 }

src/tools/slashcommand/tools.ts

@@ -24,11 +24,12 @@ function discoverCommandsFromDir(commandsDir: string, scope: CommandScope): Comm
       const content = readFileSync(commandPath, "utf-8")
       const { data, body } = parseFrontmatter(content)
 
+      const isOpencodeSource = scope === "opencode" || scope === "opencode-project"
       const metadata: CommandMetadata = {
         name: commandName,
         description: data.description || "",
         argumentHint: data["argument-hint"],
-        model: sanitizeModelField(data.model),
+        model: sanitizeModelField(data.model, isOpencodeSource ? "opencode" : "claude-code"),
         agent: data.agent,
         subtask: Boolean(data.subtask),
       }