feat: add /plan command (#1372)

* feat: add /plan command

* refactor: back /plan with bundled skill

* docs: document /plan skill

cli.py

@@ -1080,6 +1080,7 @@ from agent.skill_commands import (
     scan_skill_commands,
     get_skill_commands,
     build_skill_invocation_message,
+    build_plan_path,
     build_preloaded_skills_prompt,
 )
 
@@ -3193,6 +3194,8 @@ class HermesCLI:
         elif cmd_lower.startswith("/personality"):
             # Use original case (handler lowercases the personality name itself)
             self._handle_personality_command(cmd_original)
+        elif cmd_lower == "/plan" or cmd_lower.startswith("/plan "):
+            self._handle_plan_command(cmd_original)
         elif cmd_lower == "/retry":
             retry_msg = self.retry_last()
             if retry_msg and hasattr(self, '_pending_input'):
@@ -3304,6 +3307,31 @@ class HermesCLI:
         
         return True
     
+    def _handle_plan_command(self, cmd: str):
+        """Handle /plan [request] — load the bundled plan skill."""
+        parts = cmd.strip().split(maxsplit=1)
+        user_instruction = parts[1].strip() if len(parts) > 1 else ""
+
+        plan_path = build_plan_path(user_instruction)
+        msg = build_skill_invocation_message(
+            "/plan",
+            user_instruction,
+            task_id=self.session_id,
+            runtime_note=(
+                f"Save the markdown plan with write_file to this exact path: {plan_path}"
+            ),
+        )
+
+        if not msg:
+            self.console.print("[bold red]Failed to load the bundled /plan skill[/]")
+            return
+
+        _cprint(f"  📝 Plan mode queued via skill. Markdown plan target: {plan_path}")
+        if hasattr(self, '_pending_input'):
+            self._pending_input.put(msg)
+        else:
+            self.console.print("[bold red]Plan mode unavailable: input queue not initialized[/]")
+    
     def _handle_background_command(self, cmd: str):
         """Handle /background <prompt> — run a prompt in a separate background session.