Brains roster mobile layout fixes

Seen on Machines › Brains (/accounts) while working Task 8562. 1. A seat refused `GET /api/resources` (403) sees no rows at all; list the account names it may read from `GET /api/accounts`, with status cells blank, instead of an empty page. 2. On a phone, an expanded node row with a "Local" chip wraps "on <host>" to a line that starts left of the node icon; keep "on <host>" aligned with the name (or ellipsize it on the first line). 3. On a phone, a "no credentials" account row shows a lone ✓ on its own third line; fold the state mark onto the provider line so the row is two lines. 4. Desktop: the editable enabled toggle (circled ✓) and another org's read-only ✓ differ only by the circle; give the read-only mark a hover that names the org ("Org B — Act as to change"). 5. The 5h/7d headers stay "5H/7D" even when every visible provider uses other windows; title the columns from the providers on screen when they all agree. Out of scope: who may see or edit accounts, account sign-in rules, the account form. Done means: - Each item fixed or declined with a one-line reason in the PR. - Screenshots at 1440 px and 390 px.

Fixed all 5 Brains roster items: refused seat lists names, node host aligned, phone ✓ on provider line, org-named read-only hover, quota headers from on-screen providers. Quick gate and tests green; visual check at 1440/390 good. PR #6512 queued. Follow-up draft 8660. Memory: none applied.