vt → per-instance Terminal rendering into a pixel buffer

- Refactor vt.rs into a per-instance Terminal struct (owned cell/rendered
  grids, cursor, ANSI parser, scroll state), rendering glyphs into a
  caller-owned pixel buffer with dirty-region blitting
- Add gop buffer primitives (buffer_glyph_px, buffer_shift_up) and keep
  the legacy vt:: API as thin wrappers around the home terminal
- Remove the now-obsolete scroll hook and shadow scroll path
- Home terminal renders into its own buffer; window_id stays None until
  the WM integration lands

1 files changed, 0 insertions, 16 deletions

diff --git a/rsnix/src/wm.rs b/rsnix/src/wm.rs
index 1326696..be74f9a 100644
--- a/rsnix/src/wm.rs
+++ b/rsnix/src/wm.rs
@@ -90,8 +90,6 @@ pub fn init() {
         CASCADE_Y = 0;
     }
     FOCUSED.store(CONSOLE, Ordering::Relaxed);
-    // When the console scrolls, re-composite windows so they stay put.
-    gop::set_scroll_hook(redraw_windows);
 }
 
 /// The focused window, or `None` if the console has focus.
@@ -663,20 +661,6 @@ pub fn spawn_input_pump() -> Option<usize> {
     crate::sched::spawn(pump_main, "wm-input")
 }
 
-/// Re-composite every visible window.  Called after the console scrolls so
-/// windows stay in place while the text layer beneath them shifts.
-pub fn redraw_windows() {
-    unsafe {
-        for i in 0..ZLEN {
-            let id = ZORDER[i];
-            let w = WINDOWS[id];
-            if w.used && w.state == WinState::Visible {
-                composite_rect(w.x, w.y, w.w, w.h + TITLE_BAR_H);
-            }
-        }
-    }
-}
-
 fn pump_main() {
     loop {
         if focused().is_some() {