Pure source rename across uikit/android/android_jni/sdl3 (~64 #foreign sites):
- 30 fn decls '… #foreign;' → '… extern;'
- 34 import runtime classes '#foreign #objc_class/#jni_class("X") {' →
'#objc_class/#jni_class("X") extern {' (prefix → postfix modifier)
- 4 defined Sx* obj-c classes '#objc_class("X") {' → '… export {'
Behavior-preserving (AST already unified post-Phase-5.0). Verified byte-identical
IR via 'sx ir' on the uikit importers 1610 + 1606 (which compile uikit incl. the
4 defined Sx* classes on host) and an sdl3 probe; android.sx (host-incompatible,
only compiles under OS==.android) verified by an identical 4-error dedup set (the
keyword-neutral 'foreign symbol already bound' message is unchanged). Empty
snapshot diff; suite green (647 corpus / 444 unit, 0 failed).
2cd5d7ba82