themes: one file each, generated from helix and zed, picked by stepping a list

Each theme is a .zig file of pure data and nothing enumerates them by hand —
fold() walks the container's declarations, so a theme is a file and that is the
whole registration. Field by field rather than a wholesale coercion, which
makes a missing field a compile error that names it.

tools/gen_themes.zig reads helix .toml and zed .json out of vendor/themes and
emits one .zig each; build.zig reads that directory, so adding a theme is
dropping a file in. Output goes to the build cache rather than the tree, so zig
owns the freshness check and a deleted source cannot leave a stale theme
behind. Vendored, not read from the genizah: the build stays offline. A source
it cannot map is a hard error naming the file and the key, never a silently
black-on-black theme.

ThemeSel is the clever half. Traits gained an `executes` column, so n/N over
that buffer hands the whole line to Exec instead of the leading word to Look —
both arms the ordinary builtin, so a stepped row does exactly what the matching
mouse button on it would. Stepping the list previews each theme live. The trait
is a pane property, not an output-pane branch, so any pane whose lines are
commands can opt in.

Goldens: leader gains SPC t t; theme's fourth NextColor no longer wraps to
helix because the ring is fifteen long. New: themesel.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/themes/helix.zig b/src/themes/helix.zig
new file mode 100644
index 00000000..26c156ff
--- /dev/null
+++ b/src/themes/helix.zig
@@ -0,0 +1,47 @@
+//! Copied off the helix the user actually runs: config.toml says
+//! theme = "pardes", i.e. ~/.config/helix/themes/pardes.toml. Every value below
+//! was then PINNED against a real `hx sample.zig` render captured through a
+//! pty, not read off the TOML and hoped for — the SGR runs were 48;2;8;8;8
+//! page, 38;2;189;189;189 text, 38;2;98;98;98 line numbers, 1;38;2;207;135;232
+//! keywords, 38;2;227;199;138 strings AND numeric constants, 38;2;255;255;255
+//! comments. `zig build snap` holds them there (test/snapshots/theme.snap), so
+//! these fifteen numbers are a golden and not taste.
+//!
+//! "dark and minimal" is the half that is not a table. That theme sets no
+//! ui.statusline at all, so helix paints its status row in the page's own
+//! colors: in the capture, rows 8..23 carry one unbroken 48;2;8;8;8 run and the
+//! statusline is told apart from the file by its words alone. pardes cannot go
+//! quite that far — its tag bar is a click target and the gutter is a drag
+//! handle — so chrome lifts by the smallest honest step instead: the theme's
+//! greys are all xterm grayscale-ramp entries (232 #080808, 241 #626262,
+//! 246 #949494, 250 #bdbdbd), so the chrome takes ramp entries too — 233
+//! #121212 for the bars, 238 #444444 for the thumb, 235 #262626 for an
+//! unfocused box. No hue anywhere outside the syntax colors.
+//!
+//! Shape: bg/fg are explicit rather than null, because "just really dark" must
+//! not depend on whose terminal it lands in — but `palette` stays null so a
+//! shell's ANSI indices still resolve to the host's own 16 colors. helix does
+//! the same: it dresses the page it draws and leaves the colors a program emits
+//! alone. Only acme, which has to stay readable on yellow, resolves the palette
+//! itself.
+//!
+//! No imports, and neither has any other theme file: a theme is DATA. The
+//! `.{...}` becomes a pardes.Theme in pardes.zig's `fold`, which is also what
+//! turns a missing field here into a compile error naming it.
+pub const theme = .{
+    .name = "helix",
+    .bg = .{ 0x08, 0x08, 0x08 },
+    .fg = .{ 0xbd, 0xbd, 0xbd },
+    .tag_bg = .{ 0x12, 0x12, 0x12 },
+    .tag_fg = .{ 0x94, 0x94, 0x94 },
+    .box = .{ 0x62, 0x62, 0x62 },
+    .box_dim = .{ 0x26, 0x26, 0x26 },
+    .kw = .{ 0xcf, 0x87, 0xe8 },
+    .str = .{ 0xe3, 0xc7, 0x8a },
+    .num = .{ 0xe3, 0xc7, 0x8a },
+    .comment = .{ 0xff, 0xff, 0xff },
+    .lineno = .{ 0x62, 0x62, 0x62 },
+    .scroll_track = .{ 0x12, 0x12, 0x12 },
+    .scroll_thumb = .{ 0x44, 0x44, 0x44 },
+    .palette = null,
+};