Contract: the TUI's account and repository settings screens leave for their web pages #635

Pillar: P1 Feed (umbrella #587). Contract: one of the duplicated screens the studio/dev split left behind. One run, fresh from today's main.

The job: change account or repository settings.

Survivor: the web settings pages; the TUI says in one line where they are and opens the address.

Removed in this same pull: src/tui/screens/account.ts and src/tui/screens/settings.ts (about 1,100 lines) and their keys and tests.

The path: a person in the TUI presses the settings key; the TUI shows the web address; next the browser.

Acceptance.

• [ ] One renderer for this job, for every repository and every viewer; the other code and its tests are deleted, not hidden.
• [ ] Every old URL still answers (the survivor, or a redirect); ?mode=dev on it shows the survivor.
• [ ] Nothing the removed screen did is lost: the pull lists each thing it showed or did and where it lives now (or why nobody needs it).
• [ ] Minimal, not bare: one primary next action, white space at every width, nothing the person does not need now.
• [ ] Looks of the path at phone and desktop widths on the pull; the full check green.
• [ ] The TUI workspace, editor and review stay first-class over SSH and are untouched.

Start from: src/tui/screens/account.ts, src/tui/screens/settings.ts, src/tui/app/keys.ts, src/tui/app/app.ts.

Must not touch: the release workflow, the chart, other repositories.