Task 6 — Frontend identity and administrator UX report

RED

Added API tests for the /me principal call and mine/all session-list scopes.
Added component tests for regular-user scope, admin scope switching, owner labels, administrator banner, foreign-owner delete confirmation, and foreign-owner archive confirmation.
Initial focused run: 7 expected failures (missing getMe, missing scope query, missing owner label/admin controls, and missing foreign-action confirmation).
The archive-confirmation regression was also run separately before its implementation and failed because window.confirm was not called.

npx vitest run src/api/sessions.test.ts src/shell/NavSessions.test.tsx src/shell/AppShell.session-mgmt.test.tsx — passed (47 tests before the archive follow-up; the focused archive regression then passed).
npm test — passed: 44 files / 305 tests.
npx tsc -b — passed.
npm run build — passed.
git diff --check — passed.
npm run e2e reached Playwright but could not run: the environment has no Chromium executable at Playwright's configured cache path. No application test failure was reported.

frontend/src/api/types.ts: typed principal and session scope contracts.
frontend/src/api/sessions.ts: typed /me API call; scoped listing defaults to mine.
frontend/src/shell/AppShell.tsx: identity query, admin-only session scope selector and banner, owner-aware destructive action confirmations.
frontend/src/shell/NavSessions.tsx: owner labels in the all-sessions view.
frontend/src/api/sessions.test.ts, frontend/src/shell/NavSessions.test.tsx, and frontend/src/shell/AppShell.session-mgmt.test.tsx: contract and UX coverage.

Regular users remain fail-closed on mine; no administrator control renders without principal.isAdmin.
The all-sessions view includes owner labels (including Unknown for legacy records).
Delete confirmation preserves the pre-existing select-all behavior and adds confirmation for foreign/unknown owners. Foreign archive now also requires an explicit browser confirmation; existing Stop & save already has its confirmation dialog.
A read-only review found no critical, important, or minor issues. The archive guard was added after that review in response to the requirement to cover every destructive rail action, and has its own RED/GREEN regression plus the final full verification above.

E2E remains environment-blocked until the Playwright Chromium browser is installed.
Existing Vitest runs emit pre-existing MSW unmatched-request and dialog-ref warnings; all assertions pass and this task does not modify those shared test/UI primitives.

A post-commit review correctly identified that matching displayName must never establish ownership. The predicate now skips confirmation only when session.author exactly equals principal.subject; all display-name matches and missing authors are conservative cross-owner actions.
Added RED/GREEN regressions where two principals share display name Alice but have distinct subjects: both delete (with another session present, so select-all cannot mask the guard) and archive require confirmation.
Added aria-pressed to the My sessions / All sessions controls and asserts their selected state before and after switching.
Remediation verification: focused regressions passed; full frontend Vitest (44 files / 305 tests), npx tsc -b, npm run build, and git diff --check all passed.