feat(cli,gateway): /new accepts optional session name argument

Allow users to start a fresh session and immediately set its title by
passing a name to /new (or /reset):

    /new Refactor auth module

Changes:
- hermes_cli/commands.py: add args_hint='[name]' to /new command
- cli.py: parse title argument in process_command(), pass to new_session()
- cli.py: new_session() accepts title=None, sets title via SessionDB
- gateway/run.py: _handle_reset_command() parses title, sets on new entry
- gateway/session.py: reset_session() accepts optional display_name
- tests: add test_new_session_with_title, test_reset_command_with_title,
  test_new_command_in_help_output

All 36 affected tests pass.

cli.py

@@ -4932,7 +4932,7 @@ class HermesCLI:
         except Exception:
             pass
 
-    def new_session(self, silent=False):
+    def new_session(self, silent=False, title=None):
         """Start a fresh session with a new session ID and cleared agent state."""
         if self.agent and self.conversation_history:
             # Trigger memory extraction on the old session before session_id rotates.
@@ -4987,6 +4987,15 @@ class HermesCLI:
                     self.agent._session_db_created = True
                 except Exception:
                     pass
+                if title and self._session_db:
+                    try:
+                        from hermes_state import SessionDB
+                        sanitized = SessionDB.sanitize_title(title)
+                        if sanitized:
+                            self._session_db.set_session_title(self.session_id, sanitized)
+                            self._pending_title = None
+                    except Exception:
+                        pass
             # Notify memory providers that session_id rotated to a fresh
             # conversation. reset=True signals providers to flush accumulated
             # per-session state (_session_turns, _turn_counter, _document_id).
@@ -5006,7 +5015,10 @@ class HermesCLI:
             self._notify_session_boundary("on_session_reset")
 
         if not silent:
-            print("(^_^)v New session started!")
+            if title:
+                print(f"(^_^)v New session started: {title}")
+            else:
+                print("(^_^)v New session started!")
 
     def _handle_resume_command(self, cmd_original: str) -> None:
         """Handle /resume <session_id_or_title> — switch to a previous session mid-conversation."""
@@ -6418,7 +6430,9 @@ class HermesCLI:
                 else:
                     _cprint("  Session database not available.")
         elif canonical == "new":
-            self.new_session()
+            parts = cmd_original.split(maxsplit=1)
+            title = parts[1].strip() if len(parts) > 1 else None
+            self.new_session(title=title)
         elif canonical == "resume":
             self._handle_resume_command(cmd_original)
         elif canonical == "model":