test(windows): run the Windows code under Wine; theme preview parity

Windows was previously only compile-checked. With Wine 11 (staging)
and mingw available, scripts/windows-wine-test.sh (`just
test-windows-wine`) builds expat/FreeType/fontconfig for mingw under
target/wine-deps and runs the test suites of ghostty-vt, unicode,
datastruct, input, os, config, terminal, crash, termio and cli under
Wine (~2,700 tests). New termio/tests/exec_windows.rs drives real
cmd.exe children over ConPTY through Termio (output, exit codes,
typing, 120 KiB writes, stop, start failure). Fixes found: Windows
paths from fs::canonicalize leaked the \\?\ prefix (new
ghostty_os::path::realpath strips it like Zig); ghostty-font compiles
hb-ft for bundled HarfBuzz on Windows; ~25 tests had Unix assumptions.
Wine limitations are ignored with reasons (ResizePseudoConsole stub,
no POSIX rename over existing files) - docs/rewrite/notes/windows-wine.md.

+list-themes preview parity (former KNOWN_DIFFERENCES rows 5-9): the
search box ports vaxis TextInput (word navigation and editing bindings,
grapheme-wise editing), ASCII-only case folding, light initial colors
until terminal reports arrive (no COLORFGBG), and load errors end the
preview with exit 1; PTY tests compare with /usr/bin/ghostty.

Test Plan:
- just test-windows-wine
- cargo test -p ghostty-cli --test list_themes_pty
- cargo test --workspace --no-fail-fast (3601 passed)

crates/ghostty-os/src/i18n.rs

@@ -245,6 +245,15 @@ mod tests {
     }
 
     #[test]
+    #[cfg(windows)]
+    fn init_is_a_noop_on_windows() {
+        // i18n is unsupported on Windows (Zig returns before looking at it).
+        assert!(init(std::path::Path::new("ghostty")).is_ok());
+        assert!(init(std::path::Path::new("/")).is_ok());
+    }
+
+    #[test]
+    #[cfg(not(windows))]
     fn init_rejects_dirless_resources_dir() {
         assert!(matches!(
             init(std::path::Path::new("ghostty")),

crates/ghostty-os/src/path.rs

@@ -25,6 +25,39 @@ pub enum Error {
     Io(#[from] io::Error),
 }
 
+/// `std.fs.Dir.realpath` / `posix.realpath`: the canonical absolute path.
+///
+/// `std::fs::canonicalize` returns an extended-length `\\?\C:\...` path on
+/// Windows, while Zig's `realpath` (`GetFinalPathNameByHandle` through the NT
+/// object name) yields the plain DOS path `C:\...`. The verbatim form rejects
+/// `/` separators and is not accepted as a working directory by `cmd.exe`, so
+/// it must not leak into config values or child processes.
+pub fn realpath(path: impl AsRef<std::path::Path>) -> io::Result<PathBuf> {
+    let real = std::fs::canonicalize(path)?;
+    #[cfg(windows)]
+    let real = strip_verbatim_prefix(real);
+    Ok(real)
+}
+
+/// Turn `\\?\C:\x` into `C:\x` and `\\?\UNC\srv\share\x` into
+/// `\\srv\share\x`; other paths are returned unchanged.
+#[cfg_attr(not(windows), allow(dead_code))]
+pub(crate) fn strip_verbatim_prefix(path: PathBuf) -> PathBuf {
+    let Some(s) = path.to_str() else {
+        return path;
+    };
+    if let Some(rest) = s.strip_prefix(r"\\?\UNC\") {
+        return PathBuf::from(format!(r"\\{rest}"));
+    }
+    if let Some(rest) = s.strip_prefix(r"\\?\") {
+        let b = rest.as_bytes();
+        if b.len() >= 2 && b[0].is_ascii_alphabetic() && b[1] == b':' {
+            return PathBuf::from(rest);
+        }
+    }
+    path
+}
+
 /// Search for "cmd" in the PATH and return the absolute path. Non-UTF-8
 /// bytes are carried via [`crate::osbytes`]; see [`expand_os`].
 pub fn expand(cmd: &crate::osbytes::EncodedOs) -> Result<Option<crate::osbytes::EncodedOs>, Error> {
@@ -104,6 +137,24 @@ fn is_executable(_meta: &std::fs::Metadata) -> bool {
 mod tests {
     use super::*;
 
+    #[test]
+    fn strip_verbatim_prefix_cases() {
+        let t = |a: &str| strip_verbatim_prefix(PathBuf::from(a));
+        assert_eq!(t(r"\\?\C:\a\b"), PathBuf::from(r"C:\a\b"));
+        assert_eq!(t(r"\\?\UNC\srv\share\x"), PathBuf::from(r"\\srv\share\x"));
+        assert_eq!(t(r"\\?\GLOBALROOT\x"), PathBuf::from(r"\\?\GLOBALROOT\x"));
+        assert_eq!(t(r"C:\a"), PathBuf::from(r"C:\a"));
+        assert_eq!(t("/usr/bin"), PathBuf::from("/usr/bin"));
+    }
+
+    #[test]
+    fn realpath_has_no_verbatim_prefix() {
+        let tmp = crate::TempDir::init().unwrap();
+        let p = realpath(tmp.path()).unwrap();
+        assert!(!p.to_string_lossy().starts_with(r"\\?\"), "{p:?}");
+        assert!(p.is_dir());
+    }
+
     /// Plain-text wrapper over [`expand`] for the literals used below.
     fn expand(cmd: &str) -> Result<Option<String>, Error> {
         super::expand(&crate::osbytes::EncodedOs::from_plain_text(cmd))

crates/ghostty-os/src/xev.rs

@@ -180,7 +180,13 @@ mod tests {
         let _g = LOCK.lock().unwrap();
         detect().unwrap();
         let before = backend();
-        assert!(!prefer(Backend::Iocp));
+        // Iocp is the Windows candidate; Epoll is never one there.
+        let non_candidate = if cfg!(windows) {
+            Backend::Epoll
+        } else {
+            Backend::Iocp
+        };
+        assert!(!prefer(non_candidate));
         assert_eq!(backend(), before);
     }