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/Squirrelsong Dark

@@ -0,0 +1,22 @@
+palette = 0=#372920
+palette = 1=#ba4138
+palette = 2=#468336
+palette = 3=#d4b139
+palette = 4=#4395c6
+palette = 5=#855fb8
+palette = 6=#2f9794
+palette = 7=#d3b9a2
+palette = 8=#704f39
+palette = 9=#df4d43
+palette = 10=#659a4c
+palette = 11=#e8c23f
+palette = 12=#4ca4db
+palette = 13=#9d70da
+palette = 14=#60aca9
+palette = 15=#f2d4bb
+background = #372920
+foreground = #b19b89
+cursor-color = #b19b89
+cursor-text = #372920
+selection-background = #5b402e
+selection-foreground = #b19b89