clang-format had no config here, so adopting the submodule's puts both repos
on the same pointer alignment. .editorconfig is what lua-language-server reads
on save, which is why the Lua tree had drifted between tabs and two widths.
Apps live under /.lua/apps with data in /.lua/data, matching the runtime's
paths. ui.lua and hints.lua ship from the submodule through `make sdcard`
rather than a copy that drifts, so theme.lua and the firmware's own ui.lua
are gone.
App-visible changes: text takes a font role rather than a text size, the
theme palette names roles (color/background) instead of fg/bg, ticks are
timer.every, on_press is on_click, and centring is layout alignment now
that textAlign left the node contract.
A node was a Lua table of ~625 bytes, of which 21 keys pushed it over a
power-of-two hash boundary and eight were style copies inheritance had
splattered down from its parent. A 400 node screen cost ~250 KB and could not
coexist with wifi's buffers.
The tree now lives in src/ui/layout.h as a 16 byte struct in a flat arena, and
splits by lifetime: Node holds what hit testing and repainting need forever,
Spec holds what only measure/place read and is dropped when layout ends. Style
is sparse and resolved by walking parents, so a node naming no colours costs
nothing. Re-layout rebuilds from Lua rather than retaining the inputs.
401 nodes: 8218 B steady, 21050 B peak
Lua: ~250000 B steady
sdcard/lib/ui.lua stays the toolkit and keeps every constructor signature, but
returns integer handles: 627 lines to 374. Composition, the palette and custom
painters are still Lua on the SD card; only primitives now need a reflash.
BREAKING CHANGE: ui constructors return handles, not tables. Use
ui.setText(id, text) and keep per-node app data in a table keyed by id.
evan