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/Retro Legends

@@ -0,0 +1,22 @@
+palette = 0=#262626
+palette = 1=#de5454
+palette = 2=#45eb45
+palette = 3=#f7bf2b
+palette = 4=#4066f2
+palette = 5=#bf4cf2
+palette = 6=#40d9e6
+palette = 7=#bfe6bf
+palette = 8=#4c594c
+palette = 9=#ff6666
+palette = 10=#59ff59
+palette = 11=#ffd933
+palette = 12=#4c80ff
+palette = 13=#e666ff
+palette = 14=#59e6ff
+palette = 15=#f2fff2
+background = #0d0d0d
+foreground = #45eb45
+cursor-color = #45eb45
+cursor-text = #0d0d0d
+selection-background = #336633
+selection-foreground = #f2fff2