T16: the settings window: Cmd-, opens it or brings it forward and Cmd-W closes it, Ctrl-, and Ctrl-Shift-W off macOS; General's rows in Ely's settings layout, Shell in Ely's path input and Start in as Home or the session's folder, each change checked, saved and applied to new sessions at once; a shell saves only when it names a program, else the row says why; the app quits with its last terminal window; shot aims at either window with to:settings and to:main

AGENTS.md

@@ -16,13 +16,14 @@ ELYTerminal. A terminal on GPUI and Ely components. `PRD.md` says what it does;
   - keys as real AppKit events: `a`, `ctrl-c`, `lopt-f` and `ropt-f` (left and right Option), `cmd-v`, `repeat-up` (AppKit's repeat flag);
   - input method calls: `mark:é` composes, `commit:é` types;
   - `activate` and `deactivate` the app, which takes real keystrokes while active: keep the two specs adjacent;
+  - `to:settings` and `to:main` aim the specs after them, and the picture, at that window, which becomes the app's key window, since AppKit sends keys there; the app stays inactive;
   - mouse gestures handed to gpui's view, at points from the content's top-left, modifiers as for keys: `click@x,y`, `click2@`, `click3@`, `rclick@`, `mclick@`, `drag@x,y@x,y`, `move@x,y`, the steps `ldown@`, `lup@`, `ldrag@`, `rdown@`, `rup@`, `mdown@`, `mup@`, and `scrollup@x,y@lines`, `scrolldown@x,y@lines`.
 - `scripts/check.sh`: fmt, clippy `-D warnings`, tests, the 500-line rule.
 
 ## Layout
 
 - `src/main.rs`: start. `src/lib.rs`: the modules, public so tests and examples reach them. `src/app.rs`: fonts, settings, integration, then the main window. `src/workspace.rs`: the window's content, Ely's `ColumnShell` with the sessions, terminal and right columns, their toggles, the right column's Git and Files switch, the title, and the sessions' lifecycle. `src/sessions.rs`: a session and its row. `src/files.rs`: the Files panel, the shown session's folder as Ely's `Tree` with Git's marks. `src/git.rs`: git through its command line: Files' marks, and the Git panel's status, stage, unstage, discard, commit and log; `src/git/diff.rs` reads git's diff into Ely's stretches. `src/git/panel.rs`: the Git panel's state and actions; `src/git/panel/view.rs`: how it draws.
-- `src/settings`: the model, its ranges, and `SettingsStore`, the global that loads, checks and saves `settings.json`.
+- `src/settings`: the model, its ranges, and `SettingsStore`, the global that loads, checks and saves `settings.json`; `window` is the settings window.
 - `src/themes`: built-in terminal themes, the chrome palette each maps to, and `apply`, which dresses the app for the system's appearance.
 - `src/term`: the terminal engine. `pty` starts a program through alacritty's event loop; `tap` wraps the pty so its reader scans OSC 7 and the mouse modes before the parser. `unix` starts the program itself, so a failed `chdir` fails the start; Windows uses alacritty's ConPTY. `shell` writes the integration scripts at start and builds each shell's launch. `frame` reads the grid into styled rows, `boxes` turns box drawing, block elements and powerline arrows into rects and polygons (`boxes/outline` strokes curves and diagonals into polygons), `ink` resolves colors, `paint` draws rows, decorations and the cursor, `view` is the entity: pty events, metrics, blink, resize. `keys` turns key events into bytes, the kitty protocol and, in `keys/legacy`, xterm's encoding, with no gpui types; `input` is the view's key listeners, the bindings that keep Tab and F6 from Ely's focus moves, and its IME handler; `mac` reads the Option side and repeat flag of AppKit's current event, keeps held keys repeating, and hands Command key-ups to the focused view. `mouse` encodes mouse reports, with no gpui types; `links` finds the link at a cell; `pointer` is the view's mouse listeners: selection, reports, wheel, links, copy and paste. `find` is the find box: Ely's `FindWidget`, and Ely's `find_all` over the grid's shown text.
 - `assets/shell-integration`: ELYTerminal's own scripts (not Ghostty's, which are GPL): zsh through `ZDOTDIR`, bash through `--rcfile`, fish through `XDG_DATA_DIRS`, PowerShell through `-NoExit -Command`. Each prompt sends OSC 7 and, except in fish, whose `fish_title` stays, a title.
@@ -64,4 +65,5 @@ ELYTerminal. A terminal on GPUI and Ely components. `PRD.md` says what it does;
 - 2026-10-14: Files shows the shown session's folder in Ely's `Tree`, not `FileTree`, which takes every path up front and drops empty folders. A folder is read off the main thread when it first opens; the root and the open folders are read again whenever the session reports a folder, so at each prompt. Git's marks come from `git status --porcelain=v2 -z -- .`, run with `--no-optional-locks`, so it never holds `index.lock` against the user's own git, and under the user's `status.showUntrackedFiles`, so a home folder kept in git stays quick. An untracked folder marks what it holds. On macOS, whose file systems ignore Unicode forms, a name keeps its form on disk and meets Git's mark in composed form, as git's `core.precomposeunicode` writes it. A label built from a path shows each control character as its picture, `␊` for a newline: gpui shapes no newline, and a file may be named with one. A name not in UTF-8 keeps its bytes: its label shows it lossily, and its tree key adds the bytes after a NUL, which no path holds, so no two names share a key. A program without shell integration gets a line in the right column until it reports a folder. A control in a column header keeps its presses: Ely's header zooms the window on any double press.
 - 2026-10-14: git runs in English with `--literal-pathspecs` and without optional locks. Paths stay git's bytes until shown, so a name not in UTF-8 still names its own file; off Unix git writes UTF-8. Status reads porcelain v2. Paths to stage and unstage go in on stdin, NUL-ended (`--pathspec-from-file`), so any name and any count pass; an empty list is refused, since git would take it as the whole tree. Unstaging is `git reset`, which works before the first commit, and a staged rename unstages with its old path; a copy is a new file, its source no part of it. A diff is git's own, without external tools or text converters, a conflict against HEAD, our side, so a file we deleted reads as new; it is read into Ely's stretches; a binary file has none, and an untracked folder none either. Without an index git exits 1 for a difference and a failure alike; only a difference prints. What git warns of while it works goes to the log. The log needs a commit at HEAD: git refuses it before the first.
 - 2026-10-14: the Git panel shows HEAD's branch, or its short commit while detached; Ely's `ChangesList` of conflicted, staged, unstaged and untracked files; Ely's `CommitInput`; Ely's `CommitList` of the last 50 commits. A row's press opens its diff in Ely's fullscreen `Dialog` under the title bar, in Ely's `DiffViewer`, unified or split; a binary file, an untracked folder and a change of no line say so instead. Every control Ely draws works: stage, unstage, stage all, unstage all, amend, and discard, which asks first in Ely's `ConfirmDialog`: an edit goes back to the index (`git restore`); a new file, untracked or only intended to be added, is deleted (`git clean`, `git rm -f`). Git's clean passes over a repository of its own without a word, so a clean that removed nothing is an error. Actions run off the main thread, each after the one asked before it; a failure shows in Ely's `Alert` with git's words until dismissed or the next action, and after any action Files reads its marks again. A folder change drops the open diff, and one still loading, and blanks the view unless the new folder lies inside the shown work tree, so a cd within it does not blink; no action runs until the shown folder has read, so none reaches the repository left behind. A commit empties only the fields that still hold what it committed, and only once the shown folder has read and is in the same repository: a draft typed while it ran, or while a folder read, stays. A path shows on one line and once: as it is, or quoted as git quotes a name with control characters, quotes, backslashes or bytes not in UTF-8; a folder drops git's trailing slash, since no file shares its name. A section lists 500 files at most, and a line says how many are listed: Ely's list draws every row, and gpui copies every row's hitboxes and paint each frame, so 3000 rows halved the terminal's frames. The Git body is a cached view, so a terminal's output does not draw it again; it comes back from the Files tab with its lists scrolled to the top, since a view cached while hidden drops its widgets' state. Files stays uncached, so its tree keeps its open folders: Ely's `Tree` draws only the rows in view.
+- 2026-10-14: Cmd-, opens the settings window, or brings the open one forward, and Cmd-W closes it; off macOS Ctrl-, and Ctrl-Shift-W, as Ghostty's. Categories sit in Ely's `SettingsLayout`, rows in its `SettingsRow`; a category joins the list with its rows. Each change goes through `SettingsStore::update`, which checks and saves, and every view reads the global, so it applies at once. A shell saves only when it names a program: empty for the login shell, a file at a full path, or a name on `PATH`; else the row says why and the saved one stays, since a bad shell stops the next start. The window takes focus inside when it opens, so its keys find its context. The app quits with its last terminal window: settings alone hold no terminal.
 - 2026-10-14: settings refuse unknown fields; a bad settings file stops the start and is never overwritten.