merge the macOS app branch: the AppKit shell, pixel attachments, live theming, and mupdf -Djpx

Three commits off 38e9919 (macos-app@upstream) merged into main's ghostty bump.
No textual conflicts, and two things the merge needed:

- nested.zig asked libc for fstatat. Darwin has it; on linux std.c declares it
  `void` (glibc hides it behind a versioned symbol std cannot name), so the tty
  build stopped at 'type void not a function'. statNoFollow keeps fstatat on
  darwin and asks statx on linux for the same three fields, which is what this
  file did before the branch generalized it to both platforms.

- .DS_Store rode along with a797a1a. Deleted, and .gitignore now says so.

linux: snap 86/86, unit-test, image-harness and mupdf-check green. nested.zig
also type-checks for aarch64-macos.

1 files changed, 325 insertions, 0 deletions

diff --git a/test/macos-snapshots/keys.golden b/test/macos-snapshots/keys.golden
new file mode 100644
index 00000000..cff9484e
--- /dev/null
+++ b/test/macos-snapshots/keys.golden
@@ -0,0 +1,325 @@
+== snap typed grid=80x24 cursor=16,2
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|$ /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|  $ echo al''pha
+|
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+== snap ran grid=80x24 cursor=4,4
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|$ /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|  $ echo al''pha
+|  alpha
+|  $
+|
+|
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+== snap fixed grid=80x24 cursor=16,4
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|$ /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|  $ echo al''pha
+|  alpha
+|  $ echo bra''vo
+|
+|
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+== snap second grid=80x24 cursor=4,6
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|$ /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|  $ echo al''pha
+|  alpha
+|  $ echo bra''vo
+|  bravo
+|  $
+|
+|
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+== snap normal grid=80x24 cursor=4,6
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
+|
+|
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+== snap moved grid=80x24 cursor=7,3
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
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+== snap home grid=80x24 cursor=2,3
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
+|
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+== snap end grid=80x24 cursor=6,3
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
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+== snap pagedown grid=80x24 cursor=2,5
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
+|
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+== snap pageup grid=80x24 cursor=2,5
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
+|
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+== snap deleted grid=80x24 cursor=2,5
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|
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+== snap escaped grid=80x24 cursor=2,5
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
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+== snap tabbed grid=80x24 cursor=2,5
+|New Newcol Find Grep Help Tutor Dump NextColor Debug Kill
+|  /private/tmp/pardes-macos-e2e/keys/cwd             New Del
+|
+|  alpha
+|
+|  bravo
+|
+|  bash: bravo: command not found
+|
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