feat: TTS announcements — extended use cases (follow-up to #447)

[mholzi]

Follow-up to #447 (initial TTS implementation covers game start #16 and winner announcement #18).

Remaining use cases to implement

Game Flow

• 1. Round start — "Round 3 — get ready!"
• 2. Round countdown — "3... 2... 1..."
• 3. Round end / time'''s up — "Time'''s up!"
• 4. Correct answer reveal — "The answer was 1987!"
• 5. Nobody guessed correctly — "Nobody got it this round!"

Player Achievements

• 6. Exact guess — "Marco got it exactly right!"
• 7. Closest guess winner (Closest Wins mode) — "Anna was closest with 1985!"
• 8. Streak milestone — "Anna is on a 5-song streak!"
• 9. Streak broken — "Marco'''s streak ends at 7!"
• 10. Leader change — "Sara just took the lead!"
• 11. Tied for first — "It'''s a tie at the top!"

Betting

• 12. Bet won — "Marco doubled his points!"
• 13. Bet lost — "Risky move — Marco loses his bet!"

Game State

• 14. Player joins — "Jonas has joined the game!"
• 15. Player reconnects — "Welcome back, Lisa!"
• 17. Last round warning — "This is the final round!"
• 19. Podium finish — "3rd place: Anna. 2nd place: Sara. 1st place: Markus!"
• 20. Rematch starting — "Rematch! Get ready!"

Special Modes

• 21. Intro mode round — "Intro round — quick, you only get the opening seconds!"
• 22. Steal opportunity unlocked — "Marco unlocked steal!"
• 23. Steal used — "Marco stole points from Anna!"