@spec cursor_save_state(Raxol.Terminal.Emulator.t()) :: map()

The state DECSC saves: cursor position, visibility, style and blink, SGR attributes, charset state and (via mode_manager) origin/autowrap modes.

It does NOT include the DECSTBM scroll region: per VT100/VT510 and xterm, margins are not part of the DECSC/DECRC saved state, so a CSI t;b r emitted inside an ESC 7/ESC 8 bracket survives the restore on real hardware. This emulator used to round-trip scroll_region here, which silently un-set a region established mid-bracket (the adaptive-pin transition emits its DECSTBM inside the seal path's save/restore bracket) -- diverging from every real terminal and invalidating the O2 replay oracle. Pinned by test/harness/adaptive_pin_test.exs's transition replays and the DECRC test in state_stack_test.exs.

Handles bell control code.

Handle Backspace (BS)

@spec handle_c0(Raxol.Terminal.Emulator.t(), non_neg_integer()) ::
  Raxol.Terminal.Emulator.t()

Handles a C0 control code (0-31) or DEL (127). Delegates to specific handlers based on the codepoint.

Handle Carriage Return (CR)

@spec handle_escape(Raxol.Terminal.Emulator.t(), integer()) ::
  Raxol.Terminal.Emulator.t()

Handles simple escape sequences (ESC followed by a single byte).

Handles the Horizontal Tab (HT) action.

Handle Line Feed (LF), New Line (NL), Vertical Tab (VT)

Handle Locking Shift 1 Right (LS1R) - ESC ~ Invokes G1 character set into GR

Handle Locking Shift 2 (LS2) - ESC n Invokes G2 character set into GL

Handle Locking Shift 2 Right (LS2R) - ESC } Invokes G2 character set into GR

Handle Locking Shift 3 (LS3) - ESC o Invokes G3 character set into GL

Handle Locking Shift 3 Right (LS3R) - ESC | Invokes G3 character set into GR

Handle Reverse Index (RI) - ESC M

Handles substitute character control code.

@spec restore_cursor_save_state(Raxol.Terminal.Emulator.t(), map()) ::
  Raxol.Terminal.Emulator.t()

Applies a state saved by cursor_save_state/1. scroll_region is deliberately NOT restored -- DECRC does not touch DECSTBM margins on real terminals (see cursor_save_state/1).

@spec saved_cursor_save_state(Raxol.Terminal.Emulator.t()) :: map() | nil

The active screen's DECSC saved state, or nil.