feat: add detection of kitty multi cursor protocol support (cap_multi_cursor)

src/Loop.zig

···
                     log.info("color_scheme_updates capability detected", .{});
                     vx.caps.color_scheme_updates = true;
                 },
+                .cap_multi_cursor => {
+                    log.info("multi cursor capability detected", .{});
+                    vx.caps.multi_cursor = true;
+                },
                 .cap_da1 => {
                     std.Thread.Futex.wake(&vx.query_futex, 10);
                     vx.queries_done.store(true, .unordered);

src/Parser.zig

···
                 else => return null_event,
             }
         },
+        'q' => {
+            // kitty multi cursor cap (CSI > 1;2;3;29;30;40;100;101 TRAILER) (TRAILER is " q")
+            const second_final = sequence[sequence.len - 2];
+            if (second_final != ' ') return null_event;
+            // check for any digits. we're not too picky about checking the supported cursor types here
+            for (sequence[0 .. sequence.len - 2]) |c| switch (c) {
+                '0'...'9' => return .{ .event = .cap_multi_cursor, .n = sequence.len },
+                else => continue,
+            };
+            return null_event;
+        },
         else => return null_event,
     }
 }
···
     const actual = result.event.?.key_press;
     try testing.expectEqualStrings(expected_key.text.?, actual.text.?);
     try testing.expectEqual(expected_key.codepoint, actual.codepoint);
+}
+
+test "parse(csi): kitty multi cursor" {
+    var buf: [1]u8 = undefined;
+    {
+        const input = "\x1b[>1;2;3;29;30;40;100;101 q";
+        const result = parseCsi(input, &buf);
+        const expected: Result = .{
+            .event = .cap_multi_cursor,
+            .n = input.len,
+        };
+
+        try testing.expectEqual(expected.n, result.n);
+        try testing.expectEqual(expected.event, result.event);
+    }
+    {
+        const input = "\x1b[> q";
+        const result = parseCsi(input, &buf);
+        const expected: Result = .{
+            .event = null,
+            .n = input.len,
+        };
+
+        try testing.expectEqual(expected.n, result.n);
+        try testing.expectEqual(expected.event, result.event);
+    }
 }
 
 test "parse(csi): decrpm" {

src/Vaxis.zig

···
     color_scheme_updates: bool = false,
     explicit_width: bool = false,
     scaled_text: bool = false,
+    multi_cursor: bool = false,
 };
 
 pub const Options = struct {
···
         // why we see a Shift modifier
         ctlseqs.home ++
         ctlseqs.scaled_text_query ++
+        ctlseqs.multi_cursor_query ++
         ctlseqs.cursor_position_request ++
         ctlseqs.xtversion ++
         ctlseqs.csi_u_query ++

src/ctlseqs.zig

···
 pub const cursor_position_request = "\x1b[6n";
 pub const explicit_width_query = "\x1b]66;w=1; \x1b\\";
 pub const scaled_text_query = "\x1b]66;s=2; \x1b\\";
+pub const multi_cursor_query = "\x1b[> q";
 
 // mouse. We try for button motion and any motion. terminals will enable the
 // last one we tried (any motion). This was added because zellij doesn't

src/event.zig

···
     cap_unicode,
     cap_da1,
     cap_color_scheme_updates,
+    cap_multi_cursor,
 };