docs: design doc for fup og fakta game engine + platform architecture

Captures all brainstormed decisions:
- Pluggable game cartridge platform (GameDriver interface)
- Celery + Redis timer-driven phase transitions
- Session owner play/pause/exit controls (no skip)
- Escalating scoring per round, incremental reveal scoring
- Emoji reactions during guess phase → post-game awards
- Relational per-user config presets with game-specific models
- Ephemeral game state (no persistence after exit/finish)
- Full WebSocket event reference and data lifecycle

Also: updated TODO.md (WebSocket done, persisted answers done),
created CLAUDE.md, and PROMPT.md for ralph-loop.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lobby/views.py

@@ -20,6 +20,8 @@ from fupogfakta.models import (
     ScoreEvent,
 )
 
+from realtime.broadcast import sync_broadcast_phase_event
+
 from .i18n import api_error, lobby_i18n_errors
 
 SESSION_CODE_ALPHABET = "ABCDEFGHJKLMNPQRSTUVWXYZ23456789"
@@ -321,6 +323,16 @@ def start_round(request: HttpRequest, code: str) -> JsonResponse:
         session.status = GameSession.Status.LIE
         session.save(update_fields=["status"])
 
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.lie_started",
+        {
+            "round_number": session.current_round,
+            "category": {"slug": round_config.category.slug, "name": round_config.category.name},
+            "lie_seconds": round_config.lie_seconds,
+        },
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -407,6 +419,18 @@ def show_question(request: HttpRequest, code: str) -> JsonResponse:
 
     lie_deadline_at = round_question.shown_at + timedelta(seconds=round_config.lie_seconds)
 
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.question_shown",
+        {
+            "round_question_id": round_question.id,
+            "prompt": question.prompt,
+            "shown_at": round_question.shown_at.isoformat(),
+            "lie_deadline_at": lie_deadline_at.isoformat(),
+            "lie_seconds": round_config.lie_seconds,
+        },
+    )
+
     return JsonResponse(
         {
             "round_question": {
@@ -575,6 +599,22 @@ def mix_answers(request: HttpRequest, code: str, round_question_id: int) -> Json
             locked_session.status = GameSession.Status.GUESS
             locked_session.save(update_fields=["status"])
 
+    try:
+        _guess_config = RoundConfig.objects.get(session=session, number=session.current_round)
+        _guess_seconds = _guess_config.guess_seconds
+    except RoundConfig.DoesNotExist:
+        _guess_seconds = None
+
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.guess_started",
+        {
+            "round_question_id": round_question.id,
+            "answers": [{"text": t} for t in deduped_answers],
+            "guess_seconds": _guess_seconds,
+        },
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -719,6 +759,12 @@ def reveal_scoreboard(request: HttpRequest, code: str) -> JsonResponse:
         .values("id", "nickname", "score")
     )
 
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.scoreboard",
+        {"leaderboard": list(leaderboard), "current_round": session.current_round},
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -792,6 +838,12 @@ def finish_game(request: HttpRequest, code: str) -> JsonResponse:
 
     winner = leaderboard[0] if leaderboard else None
 
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.game_over",
+        {"winner": winner, "leaderboard": list(leaderboard)},
+    )
+
     return JsonResponse(
         {
             "session": {
@@ -898,6 +950,21 @@ def calculate_scores(request: HttpRequest, code: str, round_question_id: int) ->
         .values("id", "nickname", "score")
     )
 
+    score_deltas = [
+        {"player_id": ev.player_id, "delta": ev.delta, "reason": ev.reason}
+        for ev in score_events
+    ]
+
+    sync_broadcast_phase_event(
+        session.code,
+        "phase.scores_calculated",
+        {
+            "round_question_id": round_question.id,
+            "score_deltas": score_deltas,
+            "leaderboard": list(leaderboard),
+        },
+    )
+
     return JsonResponse(
         {
             "session": {