Break up the four giant files (~29k lines total) into focused submodule
directories, one concern per file. Pure mechanical moves — behavior is
unchanged.
- app/update.rs (9650) -> app/update/{mod,viewport,command,style,file,
dynamic,dialog,util}. The 384-arm update_inner match stays in mod.rs
with thin delegating arms; the 66 fattest arm bodies move to topic
methods. Arm set preserved exactly (384 -> 384).
- scene/mod.rs (9017) -> scene/{mod,entity,tess,hittest,layout,paper,
mspace,project,selection,modify,group_layer,preview}. The impl Scene
body is split across files via inherent-impl-per-file; struct, ctor,
fields and load-time helpers stay in the root. fn count 123 -> 123.
- app/commands.rs (6082) -> app/commands/* grouped by command family.
The 233-arm dispatch match becomes source-ordered per-family
dispatch_* handlers, preserving first-match precedence (233 -> 233).
- app/view.rs (4686) -> app/view/{mod,overlay,modal,viewcube,controls}.
Largest file drops from 9650 to 3343. Builds clean; app launches and
loads plugins with no panic.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
