[Application] Improve fastforward playback cycling

[95x8x9]

Summary

• change the fast forward control to cycle through normal, x2, and x3 playback instead of entering a one-shot fast-forward state
• update run-status messaging to show x2 fastforward, x3 fastforward, and running based on the active playback mode
• keep pause/stop/result controls aligned with the new playback-speed behavior

Related Issue

• None (application-only PR)

Area

• Engine
• Domain
• Application
• Docs
• Build
• Analysis
• Chore

Architecture Check

• I kept the dependency direction application -> domain -> engine.
• I did not add Qt UI code to src/domain.
• I did not add domain or application dependencies to src/engine.
• I used src/ as the include root.

Verification

• cmake --preset windows-debug
• cmake --build --preset build-debug
• ctest --preset test-debug
• Not run (reason below)

Not run: ctest --preset test-debug was skipped because this change only affects application-layer playback UI behavior and the app build completed successfully.

Risks / Follow-up

• this change increases simulation stepping per timer tick for x2 and x3 modes, so we should confirm the perceived speed and status text in the Qt UI manually