fix: preserve non-UTF-8 bytes in OS, config and CLI layers

Zig treats paths, arguments and environment values as byte slices; the
port converted them lossily in many places. Now (final-Z1.md):
- argv, env (incl. present non-UTF-8 values), HOME, PATH lookup,
  passwd, resources dir, TMPDIR, cgroup, config path canonicalization,
  +validate-config, +list-themes and Zig-string escapes (\xFF) keep raw
  bytes. String-based config values carry bytes via ghostty_os::osbytes,
  a bijective escape (noncharacter U+FDD0 + byte) that leaves all valid
  UTF-8 - including Nerd Font private-use icons - unchanged.
- os/file rlimit fallbacks exist on all targets.
- i18n locale canonicalization is an exact port of libintl's tables
  (e.g. pa-Guru -> pa_IN).
- New ghostty-build-info crate is the single source of version, channel,
  commit and build mode for all consumers.

Test Plan:
- cargo test -p ghostty-os -p ghostty-config -p ghostty-cli
  (incl. randomized osbytes round-trip property tests)

crates/ghostty-os/src/temp_dir.rs

@@ -8,7 +8,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use crate::file::alloc_tmp_dir;
+use crate::file::alloc_tmp_dir_os;
 
 // The amount of random bytes to get to determine our filename.
 const RANDOM_BYTES: usize = 16;
@@ -89,8 +89,8 @@ fn fill_random(buf: &mut [u8]) -> io::Result<()> {
 impl TempDir {
     /// Create the temporary directory.
     pub fn init() -> io::Result<TempDir> {
-        let parent = match alloc_tmp_dir() {
-            Some(p) => PathBuf::from(p),
+        let parent = match alloc_tmp_dir_os() {
+            Some(p) => p,
             None => std::env::current_dir()?,
         };
         // Verify the parent can be opened (Zig opens it as a Dir).