Home takes room from the current conversation tab at 19 columns

Start with internal/tui3/hometabs.go, the shared tab renderer, and the priority statement in internal/manual/chat/screen.md:192. Reproduce the 19- and 18-column cases in tmux with a conversation title beginning with T, then inspect the existing width-table and end-to-end test coverage. Done means the current tab retains a recognizable prefix, the navigation row does not wrap, boundary tests cover when home yields space, and the manual and change entry agree.

Seen on dev@debffabf6. Surfaced while verifying #1424; not introduced by it.

What happened

At the narrowest width still showing home (19 columns in the 2026-09-24 hand test), the current conversation's tab name shrinks to .. At 18 columns home disappears and the name reads T.... The manual promises that the current tab takes priority on very narrow frames.

Replication

Deterministic (no model). Open a conversation with a title beginning with T in codeaf chat under tmux. Resize to 19, then 18 columns and capture the tab row. Today 19 retains home and reduces the current tab to .; 18 gives the current name several cells. Repeat with a longer terminal as control.

Where

internal/manual/chat/screen.md:192 at dev@debffabf6 promises current-tab priority. The tab width allocation is in internal/tui3/hometabs.go and the shared tab renderer.

The fix

Reserve a readable minimum for the current tab before allocating home on the narrowest frames, or revise the priority statement if a one-character current tab is intended.

Acceptance

• e2e: at 19 and 18 columns, the current tab retains a recognizable prefix, and the navigation row fits without wrapping.
• Unit: width-table tests cover the boundary at which home yields space.
• Align screen.md and the change entry's invalidates with the chosen rule.