T04: own Unix pty so a failed chdir fails the start; closing logs and reaps

AGENTS.md

@@ -19,7 +19,7 @@ ELYTerminal. A terminal on GPUI and Ely components. `PRD.md` says what it does;
 - `src/main.rs`: start, window. `src/lib.rs`: the modules, public so tests reach them.
 - `src/settings`: the model, its ranges, and `SettingsStore`, the global that loads, checks and saves `settings.json`.
 - `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 before the parser.
+- `src/term`: the terminal engine. `pty` starts a program through alacritty's event loop; `tap` wraps the pty so its reader scans OSC 7 before the parser. `unix` starts the program itself, so a failed `chdir` fails the start; Windows uses alacritty's ConPTY.
 - `assets/themes`: Ghostty theme files copied verbatim from iTerm2-Color-Schemes (MIT, its `LICENSE` beside them).
 
 ## Rules
@@ -37,4 +37,5 @@ ELYTerminal. A terminal on GPUI and Ely components. `PRD.md` says what it does;
 - 2026-10-14: the working directory comes from OSC 7, read by a tap on the pty reader, sent by injected shell integration. vte drops OSC 7.
 - 2026-10-14: Git through the `git` command line, not libgit2.
 - 2026-10-14: license MIT, as Ely.
+- 2026-10-14: on Unix the pty is ELYTerminal's own: alacritty 0.26 ignores `chdir`'s result, so a session could start in the wrong folder. Its traits feed alacritty's event loop, keyed 0 and 1 as alacritty's private constants are; alacritty is pinned to =0.26.0 for that.
 - 2026-10-14: settings refuse unknown fields; a bad settings file stops the start and is never overwritten.