proper terminal capability negotiation

determine support for the kitty protocol and then pick output sequences
accordingly.

tested on ghostty (supports kitty) and tmux-in-ghostty (tmux does not
support kitty protocol) with shift+enter as newline.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/tui_terminal.zig b/src/tui_terminal.zig
index c4545e9..0f8b3d9 100644
--- a/src/tui_terminal.zig
+++ b/src/tui_terminal.zig
@@ -116,7 +116,13 @@ fn winchHandler(sig: posix.SIG) callconv(.c) void {
 pub const Capabilities = struct {
     /// Terminal is believed to support synchronized output (mode 2026).
     synchronized_output: bool,
-    /// Terminal is believed to support the Kitty keyboard protocol.
+    /// Whether the Kitty keyboard protocol is in effect. Initially an env-sniffed
+    /// best guess (see `detectCapabilities`); the app then runs a startup
+    /// query/response handshake (`negotiate_query`) and overwrites this with the
+    /// confirmed result — true if the terminal acknowledged Kitty flags, false
+    /// if it fell back to modifyOtherKeys. Decode logic that depends on the live
+    /// protocol reads the module-global `tui_input.kittyActive()`, which the app
+    /// keeps in sync.
     kitty_keyboard: bool,
 };