refactor(config): parse config values from raw bytes like Zig

Zig parses config values (cli/args.zig, Config.zig field parsers,
config/string.zig) from raw byte slices, and each field type decides
whether it requires UTF-8 (InvalidValue otherwise) or stores bytes. The
port escape-encoded raw bytes into Strings at the line reader and let
fields parse the escaped text, so fields could observe encoding
artifacts; successive audits kept finding such leaks (RV5-RV8).

Field parsers now receive the original bytes: text fields validate UTF-8
where Zig does, byte/path fields store bytes (EncodedOs/OsString). This
resolves all 9 RV8 findings (docs/rewrite/notes/review-rv8-codex.md),
each with a regression test: Windows path conversion fails with
BadPathName instead of substituting U+FFFD; Windows process launch uses
strict UTF-8 like Zig's Command; the WTF-8 decoder accepts paired-
surrogate encodings like Zig; literal U+FDD0 Unicode key triggers;
selection-word-chars and clipboard-codepoint-map reject invalid UTF-8;
font style / codepoint-map family names use original bytes; C title
actions forward bytes; D-Bus new-window/Flatpak conversions match Zig.
Design, sweep and validation: docs/rewrite/notes/final-bytes-refactor.md.

Also moves the bundled iTerm2-Color-Schemes license out of
resources/themes/ so +list-themes no longer lists it as a theme
(output is now byte-identical to Ghostty 1.3.1).

Done by Codex (gpt-6-astra), reviewed and verified by the orchestrator.

Test Plan:
- cargo test --workspace --no-fail-fast (3428 passed, exit 0)
- just check-macos (both), just check-windows, just check-wasm
- +show-config --default --docs, +list-keybinds, +list-actions --docs,
  +list-themes --plain compared with /usr/bin/ghostty

crates/ghostty-input/src/command.rs

@@ -31,16 +31,16 @@ use crate::binding::{
 #[derive(Debug, Clone, PartialEq)]
 pub struct Command {
     pub action: Action,
-    pub title: String,
-    pub description: String,
+    pub title: ghostty_os::osbytes::EncodedOs,
+    pub description: ghostty_os::osbytes::EncodedOs,
 }
 
 impl Command {
     pub fn new(action: Action, title: &str, description: &str) -> Command {
         Command {
             action,
-            title: title.to_string(),
-            description: description.to_string(),
+            title: title.into(),
+            description: description.into(),
         }
     }
 
@@ -75,14 +75,17 @@ impl Command {
 pub struct CommandC {
     pub action_key: String,
     pub action: String,
-    pub title: String,
-    pub description: String,
+    pub title: ghostty_os::osbytes::EncodedOs,
+    pub description: ghostty_os::osbytes::EncodedOs,
 }
 
 /// `std.ascii.orderIgnoreCase`
-fn cmp_ignore_case(a: &str, b: &str) -> std::cmp::Ordering {
-    let a = a.bytes().map(|c| c.to_ascii_lowercase());
-    let b = b.bytes().map(|c| c.to_ascii_lowercase());
+fn cmp_ignore_case(
+    a: &ghostty_os::osbytes::EncodedOs,
+    b: &ghostty_os::osbytes::EncodedOs,
+) -> std::cmp::Ordering {
+    let a = a.to_bytes().into_iter().map(|c| c.to_ascii_lowercase());
+    let b = b.to_bytes().into_iter().map(|c| c.to_ascii_lowercase());
     a.cmp(b)
 }
 
@@ -562,7 +565,7 @@ fn default_commands() -> Vec<Command> {
         Command::new(Action::Redo, "Redo", "Redo the last undone action."),
         Command::new(Action::Quit, "Quit", "Quit the application."),
         Command::new(
-            Action::Text("👻".to_string()),
+            Action::Text("👻".into()),
             "Ghostty",
             "Put a little Ghostty in your terminal.",
         ),