refactor: resolve cross-crate integration TODOs and resources discovery

Cleanup pass over items collected in docs/rewrite/INTEGRATION_TODO.md:
- OSC 133 printf-q / percent decoders live once in
  ghostty_vt::string_encoding; ghostty-os re-exports them.
- CursorStyle and clipboard codepoint map entries have one definition
  (ghostty-terminal); ghostty-config now depends on ghostty-terminal.
- ActionKey::docs() trailing blank lines fixed at the source; cli's
  workaround removed (+list-actions --docs still byte-identical).
- x11_color exposes names in original case; cli no longer re-parses
  rgb.txt.
- One cgroup scope wait loop (ghostty_os::cgroup::wait_for_scope).
- Flatpak passwd lookup implemented in ghostty-os via a local pty.
- +version shows the rustc version captured at build time.

Resources: dev builds find <workspace>/resources automatically (keeping
Ghostty's sentinel-file detection and GHOSTTY_RESOURCES_DIR);
scripts/gen-terminfo.sh (just terminfo) regenerates the compiled
terminfo; `just install [PREFIX]` installs binary, share/ghostty,
terminfo, desktop/D-Bus/systemd/metainfo files and icons.

Test Plan:
- cargo test for vt, os, config, input, cli
- diff `+list-keybinds`, `+list-actions --docs`, `+show-config --default`
  against /usr/bin/ghostty

docs/rewrite/notes/cleanup-V2.md

@@ -0,0 +1,55 @@
+# Cleanup V2
+
+## Resources (self-contained)
+- `resources/` mirrors Ghostty's `share/ghostty` plus its sibling `share/terminfo`:
+  `shell-integration/`, `themes/` (463 files copied from the installed Ghostty 1.3.1,
+  `themes/LICENSE-iTerm2-Color-Schemes` = MIT attribution, written from the upstream license;
+  no upstream copy existed on this machine, check the copyright line if it matters) and
+  `terminfo/` (compiled `xterm-ghostty`, `g/ghostty`).
+- `scripts/gen-terminfo.sh` (`just terminfo`): `cargo run -p ghostty-termio --example terminfo`
+  prints the source from `ghostty_termio::terminfo::ghostty`, `tic -x -o resources/terminfo`, then
+  compares with the installed entry via `infocmp -x` (identical).
+- `ghostty_os::resourcesdir`: Ghostty's logic unchanged (exe-relative `share/terminfo/...` sentinel,
+  `GHOSTTY_RESOURCES_DIR` first in release / fallback in debug). New last-resort (debug only): if the
+  exe lives inside the workspace this crate was compiled in (`env!("CARGO_MANIFEST_DIR")/../..`) and
+  `<workspace>/resources` has the same sentinel (`terminfo/x/xterm-ghostty`), use it. `cargo run`
+  now works without the env var.
+- Child `TERMINFO`: Zig sets `<resources>/../terminfo`. Rust prefers `<resources>/terminfo` when
+  it holds the sentinel (dev layout), else the Zig sibling path.
+- `config::theme::open` already took `ghostty_os::resources_dir()`; the dev fallback makes it work in dev.
+- `just install [PREFIX]` (default /usr/local, honours DESTDIR): bin, share/ghostty/{shell-integration,themes},
+  share/terminfo, desktop file, D-Bus + systemd units, metainfo, kio/nautilus extensions, icons
+  (templates vendored in `dist/linux`, `dist/icons`, copied from ZIG). Not covered: shell completions,
+  vim/bat syntax (no `+fish`/`+vim-syntax` generators in the Rust cli). Install tested with DESTDIR on a fake binary.
+
+## Integration items
+- vt `string_encoding` is canonical; `ghostty-os` now depends on `ghostty-vt` and re-exports it
+  (semantic_prompt's `DecodeError` = `string_encoding::Error`).
+- `binding::set::EntryFormatter` was already implemented by an adapter in `ghostty-config/src/keybinds.rs`.
+  `+list-keybinds` (plain/--default/--docs) and `+list-actions [--docs]` are byte-identical to /usr/bin/ghostty.
+  `+show-config --default [--docs]` differs only in `gtk-opengl-debug` (debug build, same as Zig).
+- config now depends on `ghostty-terminal` (terminal dev-depends on config; cargo allows it). `CursorStyle` is
+  `ghostty_terminal::cursor::Style` (ConfigField impl in config/types_a.rs); termio's `cursor_style_from_config`
+  was removed. `clipboard_codepoint_map::{Entry, Replacement}` re-export terminal formatter types; core no longer converts.
+- `ActionKey::docs()`: four docs had an extra trailing blank line (data fixed); cli `generate_plaintext` now calls
+  `helpgen_actions::generate_string`.
+- `x11_color::names()` (original case, deduped, file order); cli depends on ghostty-vt for it.
+  Note: /usr/bin/ghostty `+list-colors` output is truncated at 12297 bytes when redirected (oracle bug); the prefix is identical.
+- Pty/slave: Zig closes the slave in exactly two places (parent after successful spawn, error path) and `Pty.deinit`
+  only runs after; Rust `Exec` calls `close_slave()` after success and drops the Pty on error, so lifetimes match. Documented in pty.rs.
+- Cgroup wait loop: single `ghostty_os::cgroup::{scope_matches, wait_for_scope}` used by termio `Command` hooks and
+  apprt-gtk `pre_exec`/`post_fork`.
+- apprt-gtk stubs: in Zig 1.3.1 `application.zig` lists secure_input, close_all_windows, float_window, toggle_visibility
+  under "Unimplemented" (log warn, return false) and the command palette hides them; the Rust stubs are therefore faithful and
+  left as is. `toggle_visibility` on Window exists only for the quick terminal (as Zig). secure_input is macOS-only.
+- tmux: `HandlerState.tmux_viewer: Option<Box<Viewer>>`; DCS Enter creates, Exit drops, other notifications go to
+  `viewer.next`, `Command` -> `write_req`, `Exit` ignored, `Windows` TODO (same TODO in Zig). Test added. Renderer already sets `search_viewport_dirty`.
+- passwd Flatpak: implemented in `ghostty-os` (termio depends on os, so no termio Pty) with rustix openpt + `FlatpakHostCommand`
+  running `/bin/sh -l -c "getent passwd <name>"`; parse of shell/home is unit tested, the host call itself is untestable here.
+- `+version`: `crates/ghostty-cli/build.rs` captures `rustc --version` (number only) into `GHOSTTY_RUSTC_VERSION`.
+
+## Gate
+fmt, clippy `-D warnings` clean for the workspace except `ghostty-bench` (another agent's new crate, 3 lints) and
+`ghostty-core` integration tests under construction by V1 (lib/bin clean; fixed one `is_multiple_of` lint in core clipboard.rs).
+Tests: all crates except core integration tests and bench pass (`ghostty-core --lib` 20). One run saw
+`ghostty-termio/tests/exec_integration large_write_with_backpressure_is_delivered_in_order` fail (10s timeout) and pass on rerun: flaky/V1 area.