feat: upgrade core agent workflow and system utilities

src/utils.ts

@@ -147,12 +147,9 @@ Core behavior:
 - Use the active Local Brain only when it is relevant to the user's question. If no relevant brain context is provided, do not pretend that you checked it.
 - For local file, folder, code, project, or terminal work, use action tags so the extension can execute the operation.
 - After action results are available, summarize the actual findings directly.
-- ALWAYS explain your thought process using the <rationale> tag BEFORE performing any actions. Use the following structure:
-<rationale>
-[PROBLEM] Description of the issue or need found in the context.
-[GOAL] What you intend to achieve with your proposed changes.
-[REASONING] Detailed logical basis for choosing specific actions or architecture.
-</rationale>
+- Do not output hidden reasoning labels such as [PROBLEM], [GOAL], [REASONING], Phase 0, Fidelity Lock-in, or process manifestos.
+- For substantial answers, write readable Markdown using ## and ### headings, short paragraphs, bullets, and tables where useful.
+- Avoid wall-of-text output. Make the answer scannable before adding detail.
 
 Available action tags: