Brains phone row polish seen at 360px

Found while screenshotting Brains at 360px (Task 6725): 1. An expanded account's Description line renders raw backticks (e.g. `auth_kind='oauth'`) as literal text; render inline code or strip the backticks. 2. A collapsed account with no credentials shows a "—" in its trailing slot beside the ⋯ while the hung line already says "No credentials"; drop the dash or show a fact there. 3. Expanded, "No credentials" and "No node has reported yet" both sit under the row; say it once (e.g. fold into one line) so the empty account reads as one fact. 4. The Machines sub-tab strip at 360px starts mid-word with a faded fragment left of "Hosts" when Brains is selected; scroll so the first visible tab is whole, or show a scroll affordance. Out of scope: desktop layout; server behaviour. Done means: each item changed or declined with a one-line reason in the PR body, with a 360px screenshot per changed surface; `./dc check full` green.

Brains 360px polish: inline-code descriptions, no phone dash, one empty-state line, whole first tab in strips. Quick gate + 114 tests green; 360px check clean; PR #5693 merged (ac7c32db6), lane ran full; deploy superseded. Follow-up: Task 6806.