chore(index): remove contextInjector chat.message hook call

- Remove createContextInjectorHook from imports
- Remove contextInjector variable declaration
- Remove contextInjector["chat.message"] call
- Keep contextInjectorMessagesTransform for synthetic part injection
- Update test: prepend → synthetic part insertion verification

src/index.ts

@@ -34,7 +34,6 @@ import {
 } from "./hooks";
 import {
   contextCollector,
-  createContextInjectorHook,
   createContextInjectorMessagesTransformHook,
 } from "./features/context-injector";
 import { applyAgentVariant, resolveAgentVariant } from "./shared/agent-variant";
@@ -163,7 +162,6 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
   const keywordDetector = isHookEnabled("keyword-detector")
     ? createKeywordDetectorHook(ctx, contextCollector)
     : null;
-  const contextInjector = createContextInjectorHook(contextCollector);
   const contextInjectorMessagesTransform =
     createContextInjectorMessagesTransformHook(contextCollector);
   const agentUsageReminder = isHookEnabled("agent-usage-reminder")
@@ -327,7 +325,6 @@ const OhMyOpenCodePlugin: Plugin = async (ctx) => {
 
       await keywordDetector?.["chat.message"]?.(input, output);
       await claudeCodeHooks["chat.message"]?.(input, output);
-      await contextInjector["chat.message"]?.(input, output);
       await autoSlashCommand?.["chat.message"]?.(input, output);
       await startWork?.["chat.message"]?.(input, output);