chore(vendor): import pi 1.3.0

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: 71023aec1546d6d677a65669c5665c0927ce0dd0

third_party/pi/packages/tui/native/darwin/README.md

@@ -1,20 +1,22 @@
 # Darwin native prebuilds
 
-Build both macOS architectures from the repository root:
+Provides modifier-key state and asynchronous text, image, and file-path clipboard access using AppKit.
+
+## Building
+
+On macOS, run from the repository root:
 
 ```sh
 npm --prefix packages/tui run build:native:darwin
 ```
 
-The build uses macOS 11.0 as the arm64 deployment target and macOS 10.15 as the x86_64 deployment target. On macOS, `build.sh` finds Apple clang and the active macOS SDK through `xcrun`. Either an Intel or Apple Silicon host can build both outputs.
+The build uses Apple clang and the macOS SDK found through `xcrun`. Either Intel or Apple Silicon can build both targets: arm64 (macOS 11+) and x64 (macOS 10.15+).
 
-A non-macOS host needs a complete Darwin cross-toolchain, including a macOS SDK and a Mach-O linker. For example, an osxcross installation can be selected with `CC` and `SDKROOT`:
+Cross-building requires a Darwin toolchain with a macOS SDK and Mach-O linker, such as osxcross:
 
 ```sh
 CC=/path/to/osxcross/clang SDKROOT=/path/to/MacOSX.sdk \
   npm --prefix packages/tui run build:native:darwin
 ```
 
-The SDK must be obtained and used in accordance with Apple's license. Plain Linux or Windows clang is not enough because the addon includes and links CoreGraphics.
-
-Zig is not used here because it does not provide the Apple SDK or CoreGraphics framework stubs. It therefore does not make this build SDK-independent, and its clang driver does not currently handle this Mach-O bundle recipe as a drop-in replacement for Apple clang.
+The SDK must be obtained and used under Apple's license. Plain clang or Zig alone is not sufficient.