feat(resources): bundle color themes and compiled xterm-ghostty terminfo

Makes the resources directory self-contained like Ghostty's share/ghostty:
- themes/: the 463 iTerm2-Color-Schemes themes Ghostty 1.3.1 ships
  (release 20260216-151611-fc73ce3), with the upstream MIT license.
- terminfo/: xterm-ghostty compiled with `tic -x` from the terminfo
  source generated by ghostty-termio; `infocmp -x` is identical to the
  installed Ghostty's entry.

The generator script and resources-dir discovery changes follow in a
separate commit.

Test Plan:
- TERMINFO=resources/terminfo infocmp -x xterm-ghostty

resources/themes/Niji

@@ -0,0 +1,22 @@
+palette = 0=#333333
+palette = 1=#d23e08
+palette = 2=#54ca74
+palette = 3=#fff700
+palette = 4=#2ab9ff
+palette = 5=#ff50da
+palette = 6=#1ef9f5
+palette = 7=#ddd0c4
+palette = 8=#515151
+palette = 9=#ffb7b7
+palette = 10=#c1ffae
+palette = 11=#fcffb8
+palette = 12=#8efff3
+palette = 13=#ffa2ed
+palette = 14=#bcffc7
+palette = 15=#ffffff
+background = #141515
+foreground = #ffffff
+cursor-color = #ffc663
+cursor-text = #141515
+selection-background = #515151
+selection-foreground = #ffc663