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-config/src/macros.rs

@@ -103,22 +103,28 @@ macro_rules! config_struct {
                 }
             }
 
+            /// Parse a plain UTF-8 value supplied programmatically.
+            #[allow(dead_code)]
+            pub fn parse_field(&mut self, key: &str, value: Option<&str>) -> Result<(), $crate::cli_args::ArgError> {
+                self.parse_field_bytes(key, value.map(str::as_bytes))
+            }
+
             #[allow(dead_code)]
             /// Parse a single key/value into the matching field. Empty
             /// values reset the field to its default.
-            pub fn parse_field(
+            pub fn parse_field_bytes(
                 &mut self,
                 key: &str,
-                value: ::core::option::Option<&str>,
+                value: ::core::option::Option<&[u8]>,
             ) -> ::core::result::Result<(), $crate::cli_args::ArgError> {
                 match key {
                     $(
                         $key => {
-                            if value == ::core::option::Option::Some("") {
+                            if value == ::core::option::Option::Some(b"".as_slice()) {
                                 $crate::cli_args::ConfigField::reset(&mut self.$field, $default);
                                 return ::core::result::Result::Ok(());
                             }
-                            $crate::cli_args::ConfigField::parse_cli(&mut self.$field, value)
+                            $crate::cli_args::ConfigField::parse_bytes(&mut self.$field, value)
                         }
                     )*
                     _ => ::core::result::Result::Err($crate::cli_args::ArgError::InvalidField),
@@ -215,11 +221,11 @@ macro_rules! config_enum {
             const VALID_VALUES: ::core::option::Option<&'static [&'static str]> =
                 ::core::option::Option::Some(Self::NAMES);
 
-            fn parse_cli(
+            fn parse_bytes(
                 &mut self,
-                value: ::core::option::Option<&str>,
+                value: ::core::option::Option<&[u8]>,
             ) -> ::core::result::Result<(), $crate::cli_args::ArgError> {
-                let v = value.ok_or($crate::cli_args::ArgError::ValueRequired)?;
+                let v = $crate::cli_args::text_value(value)?.ok_or($crate::cli_args::ArgError::ValueRequired)?;
                 *self = Self::from_name(v).ok_or($crate::cli_args::ArgError::InvalidValue)?;
                 ::core::result::Result::Ok(())
             }
@@ -295,11 +301,11 @@ macro_rules! config_packed {
                 $crate::c_value::CValue::Packed(bits)
             }
 
-            fn parse_cli(
+            fn parse_bytes(
                 &mut self,
-                value: ::core::option::Option<&str>,
+                value: ::core::option::Option<&[u8]>,
             ) -> ::core::result::Result<(), $crate::cli_args::ArgError> {
-                let v = value.ok_or($crate::cli_args::ArgError::ValueRequired)?;
+                let v = $crate::cli_args::text_value(value)?.ok_or($crate::cli_args::ArgError::ValueRequired)?;
                 let mut result = <$name as ::core::default::Default>::default();
                 $crate::cli_args::parse_packed_struct_with(v, Self::NAMES, |i, b| {
                     result.set_index(i, b);