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-font/src/codepoint_map.rs

@@ -16,7 +16,7 @@ mod tests {
 
     fn desc(family: &str) -> Descriptor {
         Descriptor {
-            family: Some(family.to_string()),
+            family: Some(family.into()),
             ..Default::default()
         }
     }
@@ -35,11 +35,27 @@ mod tests {
         // Exact range
         assert!(m.get(1).is_none());
         m.add(entry(1, 1, "A"));
-        assert_eq!("A", m.get(1).unwrap().family.as_deref().unwrap());
+        assert_eq!(
+            "A",
+            m.get(1)
+                .unwrap()
+                .family
+                .as_ref()
+                .map(ghostty_os::osbytes::EncodedOs::as_encoded)
+                .unwrap()
+        );
 
         // Later entry takes priority
         m.add(entry(1, 2, "B"));
-        assert_eq!("B", m.get(1).unwrap().family.as_deref().unwrap());
+        assert_eq!(
+            "B",
+            m.get(1)
+                .unwrap()
+                .family
+                .as_ref()
+                .map(ghostty_os::osbytes::EncodedOs::as_encoded)
+                .unwrap()
+        );
 
         // Non-matching
         assert!(m.get(0).is_none());
@@ -47,8 +63,24 @@ mod tests {
 
         m.add(entry(3, 4, "C"));
         m.add(entry(5, 6, "D"));
-        assert_eq!("C", m.get(3).unwrap().family.as_deref().unwrap());
-        assert_eq!("B", m.get(1).unwrap().family.as_deref().unwrap());
+        assert_eq!(
+            "C",
+            m.get(3)
+                .unwrap()
+                .family
+                .as_ref()
+                .map(ghostty_os::osbytes::EncodedOs::as_encoded)
+                .unwrap()
+        );
+        assert_eq!(
+            "B",
+            m.get(1)
+                .unwrap()
+                .family
+                .as_ref()
+                .map(ghostty_os::osbytes::EncodedOs::as_encoded)
+                .unwrap()
+        );
     }
 
     #[test]