fix: Windows core build, embedded init, byte-exact paths, version info

Closes the remaining core/lib/termio/GTK rows (final-Z2.md):
- ghostty-core compiles for Windows (Unix-only exec fields and file
  modes gated); checked with cargo check --target x86_64-pc-windows-gnu.
- Embedded init: ensure_locale, SIGPIPE ignored in ghostty_init for
  C/Swift hosts, Apple crash tags; the argv passed to ghostty_init feeds
  ghostty_config_load_cli_args; ghostty_config_load_file accepts
  non-UTF-8 paths.
- OSC 7 pwd, embedded surface cwd/command/env/initial input,
  ghostty_surface_text and GTK file drops keep raw bytes.
- XTVERSION, TERM_PROGRAM_VERSION, the About dialog and crash metadata
  use ghostty_build_info instead of hardcoded versions.

Test Plan:
- cargo test --workspace (3327 passed)
- cargo clippy --workspace --all-targets -- -D warnings

crates/ghostty-lib/src/config_capi.rs

@@ -249,9 +249,10 @@ pub unsafe extern "C" fn ghostty_config_load_file(ptr: ghostty_config_t, path: *
         return;
     }
     // SAFETY: `path` is NUL terminated.
-    let path = unsafe { CStr::from_ptr(path) }
-        .to_string_lossy()
-        .into_owned();
+    // Non-UTF-8 file names are valid on Unix; keep the bytes (reversible
+    // escape understood by the config file loader).
+    let path =
+        ghostty_os::osbytes::bytes_to_config_string(unsafe { CStr::from_ptr(path) }.to_bytes());
     if let Err(err) = c.config.load_file(&path) {
         log::error!("error loading config from file path={path} err={err}");
     }