Browser bridge in the core (shared by the Mac and desktop apps); webpki security update

- crates/kv-ipc: native-messaging framing and the local IPC socket/pipe (moved from kestrove-desktop),
  plus Listener::bind_in/connect_in and, on macOS, the App Group socket for the kestrove-nmh bundled
  in Kestrove.app (Contents/Resources/kestrove-app-group).
- crates/kv-nmh: the native-messaging host, with an embedded Info.plist on macOS so it can run
  sandboxed (KV_NMH_BUNDLE_ID).
- kv-ffi feature browser-bridge: broker, pairing channel and word list (moved from kestrove-desktop)
  and BrowserBridge for Swift. build-apple.sh enables it and builds a universal kestrove-nmh.
- RUSTSEC-2026-0381/0382: rustls-webpki 0.103.16, webpki-roots 1.0.10 (distrusted emSign roots).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/kv-ipc/Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "kv-ipc"
+description = "Local IPC and native-messaging framing between kestrove-nmh and the app that serves the browser extension."
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+publish.workspace = true
+
+[dependencies]
+serde_json.workspace = true
+
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.61", features = [
+  "Win32_Foundation",
+  "Win32_Security",
+  "Win32_Security_Authorization",
+  "Win32_Storage_FileSystem",
+  "Win32_System_Pipes",
+  "Win32_System_Threading",
+] }
+
+[dev-dependencies]
+tempfile.workspace = true