fix(web): remove logout route

[GHX5T-SOL]

Summary

• remove the dedicated /logout route and view
• make authenticated Z shortcut logout immediately
• make command-palette logout actions call the same logout path directly
• isolate logout tests so they exercise the real logout hook instead of competing alias mocks

Closes #1793

Validation

• bun test --cwd packages/web src/auth/compass/hooks/useLogout.test.ts src/common/hooks/useLogoutCmdItems.test.ts src/views/Week/hooks/shortcuts/useGlobalShortcuts.test.tsx (7 pass)
• bun test:web (passed)
• bun test:core (passed)
• bun test:backend (passed when rerun alone; the first parallel run with scripts collided on Jest MongoDB globalConfig cleanup)
• bun test:scripts (passed)
• bun type-check (passed)
• bun lint (passed)
• git diff --check (passed)

Notes

• GitHub currently reports no checks for this branch via gh pr checks 1794.