fix(agents): restrict OmO-Plan to read-only tools, inherit from default plan agent (#72)

Remove OmO agent permission spread from omoPlanBase to ensure OmO-Plan:
- Uses read-only tools only (read, glob, grep, etc)
- Focuses on planning and analysis
- Can ask follow-up questions for clarification
- Does not execute code changes

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

src/index.ts

@@ -312,7 +312,6 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
         const { name: _planName, ...planConfigWithoutName } = config.agent?.plan ?? {};
         const omoPlanOverride = pluginConfig.agents?.["OmO-Plan"];
         const omoPlanBase = {
-          ...builtinAgents.OmO,
           ...planConfigWithoutName,
           description: `${config.agent?.plan?.description ?? "Plan agent"} (OhMyOpenCode version)`,
           color: config.agent?.plan?.color ?? "#6495ED",