fix(core): wrap kitty graphics query in tmux DCS passthrough

Fixes #334

- Re-enable kitty graphics query (was disabled due to tmux pane title corruption)
- Wrap query in tmux DCS passthrough when TMUX env var is present
- Skip query for TERM=screen*/tmux* without TMUX (could be GNU Screen)
- Add OPENTUI_NO_GRAPHICS env var to disable query manually

Author: edlsh

packages/core/src/zig/ansi.zig

@@ -89,6 +89,8 @@ pub const ANSI = struct {
     pub const decrqmColorScheme = "\x1b[?2031$p";
     pub const csiUQuery = "\x1b[?u";
     pub const kittyGraphicsQuery = "\x1b_Gi=31337,s=1,v=1,a=q,t=d,f=24;AAAA\x1b\\\x1b[c";
+    // tmux DCS passthrough variant (ESC chars doubled) to avoid pane title corruption (#334)
+    pub const kittyGraphicsQueryTmux = "\x1bPtmux;\x1b\x1b_Gi=31337,s=1,v=1,a=q,t=d,f=24;AAAA\x1b\x1b\\\x1b\x1b[c\x1b\\";
     pub const sixelGeometryQuery = "\x1b[?2;1;0S";
     pub const cursorPositionRequest = "\x1b[6n";
     pub const explicitWidthQuery = "\x1b]66;w=1; \x1b\\";

packages/core/src/zig/terminal.zig

@@ -63,6 +63,9 @@ pub const TerminalInfo = struct {
 caps: Capabilities = .{},
 opts: Options = .{},
 
+in_tmux: bool = false,
+skip_graphics_query: bool = false,
+
 state: struct {
     alt_screen: bool = false,
     kitty_keyboard: bool = false,
@@ -177,14 +180,17 @@ pub fn queryTerminalSend(self: *Terminal, tty: anytype) !void {
 
         // Version and capability queries
         ansi.ANSI.xtversion ++
-        ansi.ANSI.csiUQuery ++
-        // Kitty graphics detection: sends dummy query + DA1
-        // Terminal will respond with ESC_Gi=31337;OK/ERROR ESC\ if supported, or just DA1 if not
-        // NOTE: deactivated temporarily due to issues with tmux showing the query as pane title
-        // ansi.ANSI.kittyGraphicsQuery ++
-        ansi.ANSI.restoreCursorState
-            // ++ ansi.ANSI.sixelGeometryQuery
-    );
+        ansi.ANSI.csiUQuery);
+
+    if (!self.skip_graphics_query) {
+        if (self.in_tmux) {
+            try tty.writeAll(ansi.ANSI.kittyGraphicsQueryTmux);
+        } else {
+            try tty.writeAll(ansi.ANSI.kittyGraphicsQuery);
+        }
+    }
+
+    try tty.writeAll(ansi.ANSI.restoreCursorState);
 }
 
 pub fn enableDetectedFeatures(self: *Terminal, tty: anytype, use_kitty_keyboard: bool) !void {
@@ -221,20 +227,29 @@ pub fn enableDetectedFeatures(self: *Terminal, tty: anytype, use_kitty_keyboard:
 }
 
 fn checkEnvironmentOverrides(self: *Terminal) void {
+    self.in_tmux = false;
+    self.skip_graphics_query = false;
+
     var env_map = std.process.getEnvMap(std.heap.page_allocator) catch return;
     defer env_map.deinit();
 
     // Always just try to enable bracketed paste, even if it was reported as not supported
     self.caps.bracketed_paste = true;
 
     if (env_map.get("TMUX")) |_| {
+        self.in_tmux = true;
         self.caps.unicode = .wcwidth;
     } else if (env_map.get("TERM")) |term| {
         if (std.mem.startsWith(u8, term, "tmux") or std.mem.startsWith(u8, term, "screen")) {
+            self.skip_graphics_query = true; // could be GNU Screen, not safe to send kitty query
             self.caps.unicode = .wcwidth;
         }
     }
 
+    if (env_map.get("OPENTUI_NO_GRAPHICS")) |_| {
+        self.skip_graphics_query = true;
+    }
+
     // Extract terminal name and version from environment variables
     // These will be overridden by xtversion responses if available
     if (!self.term_info.from_xtversion) {