style: trim CSI-u shortcut comments

Maintainer edit: simplify the explanatory comments for the CSI-u shortcut while preserving the existing behavior and regression coverage.

nanobot/cli/commands.py

@@ -310,28 +310,12 @@ def _build_cli_key_bindings() -> KeyBindings:
       * Enter       -> submit the current input (keeps the familiar
                        single-line Enter-to-send feel even though the buffer
                        is multiline-capable).
-      * Alt+Enter   -> insert a newline for multi-line input. Universally
-                       supported, so this is the reliable multiline shortcut.
+      * Alt+Enter   -> insert a newline for multi-line input.
       * Shift+Enter -> insert a newline on terminals that emit the CSI-u
                        (kitty / fixterms) keyboard-protocol encoding for it.
     """
-    # Terminals speaking the CSI-u (kitty / fixterms) keyboard protocol -- e.g.
-    # kitty, Ghostty and WezTerm when it is enabled -- send Shift+Enter as the
-    # escape sequence "\x1b[13;2u". prompt_toolkit 3.0 has no support for that
-    # protocol (no way to negotiate it, no default mapping for the sequence), so
-    # when such a terminal sends it the Vt100Parser fails to recognise the
-    # sequence and dumps the raw bytes ("^[[13;2u") straight into the buffer.
-    #
-    # Register the sequence so it parses as one keypress bound to insert a
-    # newline instead. "\x1b[13;2u" is absent from prompt_toolkit's default
-    # ANSI_SEQUENCES table, so this is a pure addition -- setdefault() overrides
-    # nothing -- carried on Keys.ControlF3, an enum member prompt_toolkit
-    # declares but never wires to a default sequence or binding.
-    #
-    # This is best-effort: without protocol negotiation we can only *react* to a
-    # CSI-u sequence a terminal already emits, not *request* one. Terminals that
-    # collapse Shift+Enter into a plain Enter are indistinguishable and fall back
-    # to Alt+Enter, which is why Alt+Enter stays the primary shortcut.
+    # prompt_toolkit does not recognize CSI-u, so register its Shift+Enter
+    # sequence as a best-effort addition without overriding existing mappings.
     with suppress(Exception):
         from prompt_toolkit.input import ansi_escape_sequences as _aes
 

tests/cli/test_cli_input.py

@@ -129,12 +129,7 @@ async def test_alt_enter_inserts_newline_on_lf_terminals():
 
 @pytest.mark.asyncio
 async def test_csi_u_shift_enter_inserts_newline_not_raw_escape():
-    """Terminals speaking the CSI-u (kitty / fixterms) keyboard protocol send
-    Shift+Enter as "\\x1b[13;2u". prompt_toolkit has no support for that protocol
-    and would otherwise dump the raw escape bytes ("^[[13;2u") into the buffer;
-    the binding must instead parse it as one keypress and insert a newline. Only
-    a real PromptSession/parser exercises the ANSI_SEQUENCES registration.
-    """
+    """CSI-u Shift+Enter inserts a newline instead of raw escape bytes."""
     from prompt_toolkit.application import create_app_session
     from prompt_toolkit.input import create_pipe_input
     from prompt_toolkit.output import DummyOutput