The keyboard notification callback. First standalone exercises of
`#objc_call(CGRect)` (HFA — structurally equivalent to UIEdgeInsets,
already verified by 1.25 and ffi-objc-call-07) and `#objc_call(u64)`
(LLVM-equivalent to s64; ffi-objc-call-04 already locks in the i64
return path).
Migrates:
- `userInfo` (*void)
- `objectForKey:` with NSString arg (*void)
- `CGRectValue` (CGRect HFA)
- `doubleValue` (f64)
- `unsignedLongValue` (u64)
- `screen` (*void)
- `bounds` (CGRect HFA)
Net -14 lines. uikit.sx now 854 lines (-83 cumulative across Phase 1D).
iOS-sim chess regression smoke: launch is clean; the callback is
registered through cluster 1.30's notification-center wiring and the
function lowers without IR-verifier complaints. The callback body
itself isn't exercised at runtime by chess startup (the game doesn't
open the soft keyboard) — runtime verification of this specific
function is transitive via the other clusters that exercise the same
call shapes.
e1d300c661