Audit › Sessions: quieter rows and filters for a refused-model session

Seen while checking Task 7983 on Audit › Sessions and the pane-log page (local stack, a Bedrock `model_refused` row). Suggestions: 1. A row whose end names a terminal break cause (e.g. "Model not available to the account") also stacks "No events received" in red and "The transcript could not be read from the node"; demote or fold these when the cause already explains them, so the cause line is the only alarm. 2. The pane log's fold marker `[×N]` (and a lone countdown like `1 [×8]`) is unexplained; add a one-line caption or tooltip saying N repeated retry frames were folded. 3. Sessions has no End reason filter; add one (break causes included) so an operator can list every `model_refused` run. 4. The status marker glyph for a transcript `unavailable` row is a bare "?"; give it the same reason text on hover/tap that the row's last line carries. Out of scope: pane-log rendering rules and how end reasons are recorded (Task 7983 settled those). Done means: each item addressed or declined with a reason; a screenshot of a refused-model Sessions row and its pane log after, desktop and 390px.

All 4 items shipped in PR #6275, queued to the merge lane: End reason filter (by shown reason), folded alarms under a terminal cause, tap reason on the transcript disc, pane-log [×N] caption. Quick gate and changed-area tests green. Visual check done at desktop and 390px. Follow-ups filed as draft #8048.