#436 dash: the live decisions feed is silent to screen readers

[Anonymous]

Originally created by: fu351

#pending-list already carries aria-live="polite" (src/doberman/dash/app.py:272), so a screen reader announces new pending approvals. The Recent decisions list right under it, <ul id="feed"></ul> (:275), has no aria-live, so decisions streamed in over SSE are never announced. (#260 is about the tkinter dialog, a different surface; this one is the web dashboard.)

What to do

1. Add aria-live="polite" to the <ul id="feed"> tag, mirroring #pending-list.
2. Test in tests/unit/test_dash_polish.py: the served shell contains id="feed" aria-live="polite" (or the attribute in whichever order you write it).

One attribute. Heads-up: [#401] and [#415] are in flight against dash/app.py; branch from a fresh main.