Add Ratatui terminal application

TESTING.md

@@ -1,11 +1,11 @@
 # Testing Gotcha
 
-This document is the source of truth for iOS visual verification. Every UI
-change must update its relevant scenarios in the same commit. For ordinary
-commits, run the build gates and every scenario affected by the change. A
-release test means completing this entire checklist successfully on the stated
-simulators and devices; record failures as open issues and do not sign off until
-every scenario passes.
+This document is the source of truth for iOS and terminal UI verification.
+Every UI change must update its relevant scenarios in the same commit. For
+ordinary commits, run the build gates and every scenario affected by the
+change. A release test means completing this entire checklist successfully on
+the stated terminals, simulators, and devices; record failures as open issues
+and do not sign off until every scenario passes.
 
 ## Test record
 
@@ -38,6 +38,43 @@ cargo clippy --workspace --all-targets -- -D warnings
 cargo test --workspace
 ```
 
+## Terminal UI
+
+Run `cargo run -p gotcha-tui -- --server NAME` in a normal terminal and in a
+Herdr pane. Use a non-production account with at least two server profiles and
+representative repositories.
+
+- [ ] The five numbered panes open Home, Issues, Repos, PRs, and Milestones;
+      the selected pane and row remain visibly distinct at narrow and wide
+      terminal sizes.
+- [ ] `j`/`k`, arrows, `g`/`G`, Page Up/Down, Enter, Backspace, and `q` provide
+      mutt-style list and history navigation; `n`/`p` and scrolling past a
+      boundary traverse paginated API results without losing history.
+- [ ] Clicking a pane switches it, clicking a list row selects it,
+      double-clicking opens it, and the mouse wheel scrolls the list.
+- [ ] Home activity filters cycle with `v`; activity targets route to their
+      repository, issue, pull request, or commit.
+- [ ] Repository favorites toggle with `*`, sort first per pane, and persist
+      after relaunch. Commits switch branches with `b`; file trees, text and
+      binary files, commit changes, pull changes, and per-file diffs open.
+- [ ] Issue and pull filters apply. Issues can be created, edited,
+      closed/reopened, and deleted after confirmation; issue comments can be
+      added and the current user's comments edited.
+- [ ] Milestones can be created, edited, closed/reopened, and deleted after
+      confirmation; milestone details route to their issues and pulls.
+- [ ] Server profiles can be added, authenticated, selected, edited, renamed,
+      and deleted. Blank token on edit preserves the existing token; removing
+      the last server leaves the server manager available.
+- [ ] Editors move between fields with Tab/Shift-Tab, support cursor movement,
+      Unicode insertion, Delete, and Backspace without navigating back, mask
+      tokens, save with Ctrl-S, and cancel with Esc.
+- [ ] The default overview refresh interval is five seconds. Changing it with
+      `,` persists after relaunch; refresh preserves selection and pauses while
+      editing, confirming, scrolling, or otherwise interacting.
+- [ ] `cargo build --release -p gotcha-tui` produces
+      `target/release/gotcha-tui`, and the installed executable starts from
+      `PATH`.
+
 Build and install the simulator app:
 
 ```sh