feat(renderer): add post-session unknown activity review

[lukitasxue]

Summary

Adds the post-session review screen for unknown activity detected during Deep Sesh sessions.

After a session stops or completes, Taskmaster can slide from the Pomodoro timer into a review UI where the user decides what to do with newly detected apps/pages. This keeps the active Pomodoro screen clean while still letting the monitoring system learn from unknown activity.

What changed

• Adds an end-of-session review screen for unknown apps/pages.
• Lets the user choose Allow, Block, or Ignore for detected unknown activity.
• Adds a Do later action so unresolved unknown items can stay pending for a future session.
• Enables Continue once the user has selected at least one item.
• Shows a confirmation if the user continues while some unknown items are still unresolved.
• Adds slide/transition styling so the review screen feels like a separate post-session step.
• Keeps the Pomodoro/timer layout clean during active sessions.

Behavior notes

• Unchosen items are not ignored automatically.
• If the user chooses Do later, unknown items remain unknown.
• If the user only reviews some items, the remaining ones stay pending and can appear again later.
• This PR does not add new monitoring detection logic; it uses the focus monitor state introduced by the previous PR.

Test plan

• Start a Deep Sesh/Pomodoro session.
• Open an unknown app or browser page.
• Stop or finish the session.
• Confirm the UI slides into the review screen.
• Choose Allow, Block, or Ignore for one item.
• Confirm Continue becomes enabled.
• Continue with unresolved items and confirm the warning appears.
• Confirm Do later returns to the timer flow without discarding unknowns.
• Run:
  • cd electron
  • npm run lint
  • npm run build