* fix(studio-server): freeze still appears whole, so a slow extraction cannot break its undo
The freeze route reserved the still's final name with an empty file before
ffmpeg ran. When extraction outlasted the history's quiet time, history
committed that empty file as an outside change, and Cmd+Z then restored a
0-byte PNG. ffmpeg now writes under an atomic temp name the history skips,
and the still is published with createFileAtomically (EEXIST still refuses
a taken name).
* fix(core): a direct exclusive write that fails midway leaves no partial file
Without hard links, createFileAtomically writes the destination directly.
A full disk then left a partial file behind (a corrupt upload or freeze
still); it is now removed, and a name another writer holds is never
touched. Freeze tests: the slow-extraction test leaves a half-written temp
file while history commits, and concurrent extractions meet at a barrier
instead of a real timer.
* fix(core): a quota reported only at close still removes the partial file
* test(core): the direct write closes once and keeps its write error when cleanup fails
* test(core): a failed direct write closes its descriptor exactly once
* refactor(studio-server): freeze names carry what their comments said
* fix: a save's temp file no longer reaches Studio as an outside change
* refactor: the project file walk and its tests carry no new duplication or complexity
* test(studio): the edit accuracy gate judges the two nudge sequences again
* fix: readers never see an empty or half-written project file
* test: pin the create routes and block install to whole-file writes
* fix(sdk): a write through a link to a missing file creates that file
* fix: saves through a linked folder reach the real file, atomic writes handle long names
* test(sdk): check for the stray file, not the folder listing
* fix(core): creates work on Windows FAT drives, and links through folders resolve as the system does
* fix: agree the helper move in the deletion check, and match temp paths without a path regex
* test: check POSIX file modes only off Windows
Miguel Ángel