feat(hooks): implement UserPromptSubmit with chat.message hook and injectHookMessage

- Add chat.message handler to createClaudeCodeHooksHook factory
- Integrate executeUserPromptSubmitHooks() for user prompt processing
- Use injectHookMessage() for file system based message injection
- Add sessionFirstMessageProcessed tracking for title generation skip
- Register chat.message hook in plugin entry point

This completes 100% port of Claude Code hooks from opencode-cc-plugin.

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

src/index.ts

@@ -86,6 +86,10 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
   return {
     tool: builtinTools,
 
+    "chat.message": async (input, output) => {
+      await claudeCodeHooks["chat.message"]?.(input, output)
+    },
+
     config: async (config) => {
       const builtinAgents = createBuiltinAgents(
         pluginConfig.disabled_agents,