Audit event page: trim repeated header facts and name the session

Noticed while visually checking Task 7977's Audit event page (`apps/web/src/pages/audit/AuditEventPage.tsx`) on the live stack at 390px and 1280px. Suggestions: 1. The header subtitle ("project Audit check") repeats the title's own subject ("Created project Audit check"); drop the subtitle line when the sentence already names the subject. 2. "Event id" repeats the breadcrumb's "Event 3"; show it as a copyable id (as other detail pages' `CopyableIdField`) or drop the field. 3. "Session" shows a raw 16-hex token above its link; make the link the value and keep the token as secondary text, matching Account/Actor. 4. At 390px the Actor and Account secondary ids wrap mid-UUID onto two lines; a copy button with an ellipsised id would read cleaner. Out of scope: what caller facts are recorded; the audit list pane. Done means: - A 390px and a 1280px screenshot of the Event tab show none of the repeats above. - AuditEventPage vitest suite green. Required checks: ./dc check full

Audit event page: subtitle subject hidden when the sentence names it, Event id dropped, session link leads with token beneath, ids one-line ellipsised + copy. Quick gate + audit vitest green; visual check 390/1280 clean. PR #6254 queued in lane. Follow-up draft #8010.