fix(acp): sync native agent session titles (#1028)

* fix(acp): sync native session titles

* fix(acp): keep title refresh off turn path

* fix: reconcile native ACP titles with skill lookup

* fix: preserve OpenCode image tool instruction

cli/src/opencode/utils/systemPrompt.ts

@@ -17,6 +17,15 @@ export const TITLE_INSTRUCTION = trimIdent(`
     ${SKILL_LOOKUP_INSTRUCTION}
 `);
 
+/**
+ * Tool instructions for native ACP sessions. Title updates come from ACP, so
+ * advertise only the MCP tools that remain available to the model.
+ */
+export const OPENCODE_NATIVE_TOOL_INSTRUCTION = trimIdent(`
+    When you create or find a local image file that the user should see, call the tool "hapi_display_image" with the image path so HAPI can show it inline.
+    ${SKILL_LOOKUP_INSTRUCTION}
+`);
+
 /**
  * The system prompt to inject for OpenCode sessions.
  */