docs: replace session logging boilerplate with marker file pointer

Redundant session start procedures now provided by AGENTS-README-FIRST.yaml.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: sharpninja

.github/copilot-instructions.md

@@ -1,21 +1,3 @@
 # Copilot Instructions — GrapghRAG
 
-## ⚠️ PRIORITY ORDER — NON-NEGOTIABLE ⚠️
-
-**Speed is never more important than following workspace procedures.**
-
-Before doing ANY work on ANY user request, you MUST complete these steps in order:
-
-3. **POST `/mcp/sessionlog`** with your session entry — do NOT proceed until this succeeds
-4. **GET `/mcp/sessionlog?limit=5`** to review recent session history for context
-5. **GET `/mcp/todo`** to check current tasks
-6. **THEN** begin working on the user's request
-
-On EVERY subsequent user message:
-1. POST an updated session log entry BEFORE starting work
-2. Complete the user's request
-3. POST the final session log with results, actions taken, and files modified
-
-**If you skip any of these steps, STOP and go back and do them before continuing.**
-Session logging is not optional, not deferred, and not secondary to the task.
-Failure to maintain the session log is a compliance violation.
+See `AGENTS-README-FIRST.yaml` in the workspace root for MCP server connection details, session logging procedures, and agent conduct guidelines.