feat: add Prism snake and gameplay database lifecycle

- Add bitboard-accelerated Prism and versioned Supreme snake implementations.
- Add database-backed move benchmarks and focused strategy tests.
- Normalize gameplay storage while preserving replay compatibility.
- Add deterministic game quality scoring and replay retention tiers.
- Add backup-first SQLite cleanup, verification, and replacement tooling.
- Add safe compact-plus-delta database merging with conflict detection.
- Extend SQLite and PostgreSQL schemas for replay and quality metadata.
- Add PostgreSQL development service and pytest import configuration.
- Update gameplay documentation and the quart_common submodule revision.

server/database/normalized_turn.py

@@ -0,0 +1,84 @@
+"""Normalized gameplay turn storage and replay hydration.
+
+A turn is split into one board row plus one snake row per participating snake.
+Static snake identity belongs to ``game_snakes``. This avoids storing complete
+snake payloads in the board, snakes, you, and snake-turn columns simultaneously.
+"""
+
+from typing import Callable
+
+def compact_turn_json(board:dict) -> tuple[dict, list, dict, list, list]:
+  """Return compatibility JSON plus canonical food and hazard values."""
+  return {}, [], {}, board.get("food", []), board.get("hazards", [])
+
+def hydrate_replay_turns(game_row, turn_rows, snake_rows, decode_json:Callable) -> list[dict]:
+  rows_by_turn:dict[int, list] = {}
+  for row in snake_rows:
+    rows_by_turn.setdefault(int(row["turn"]), []).append(row)
+
+  turns = []
+  for row in turn_rows:
+    turn = int(row["turn"])
+    stored_board = decode_json(row["board_state_json"]) or {}
+    food = decode_json(row["food_json"])
+    hazards = decode_json(row["hazards_json"])
+
+    snakes = []
+    api_snakes = []
+    for snake_row in rows_by_turn.get(turn, []):
+      body = decode_json(snake_row["body_json"]) or []
+      api_snake = {
+        "id": snake_row["snake_id"],
+        "name": snake_row["snake_name"],
+        "health": snake_row["health"],
+        "length": snake_row["length"],
+        "head": {"x": snake_row["head_x"], "y": snake_row["head_y"]},
+        "body": body,
+      }
+      if snake_row["latency"] is not None:
+        api_snake["latency"] = snake_row["latency"]
+      api_snakes.append(api_snake)
+      snakes.append({
+        "snake_id": snake_row["snake_id"],
+        "snake_name": snake_row["snake_name"],
+        "health": snake_row["health"],
+        "length": snake_row["length"],
+        "head": api_snake["head"],
+        "body": body,
+        "is_you": bool(snake_row["is_you"]),
+        "inferred_move": snake_row["inferred_move"],
+        "latency": snake_row["latency"],
+      })
+
+    board = stored_board or {
+      "width": game_row["width"],
+      "height": game_row["height"],
+      "food": food or [],
+      "hazards": hazards or [],
+      "snakes": api_snakes,
+    }
+    if food is None:
+      food = board.get("food", [])
+    if hazards is None:
+      hazards = board.get("hazards", [])
+
+    you = decode_json(row["you_json"]) or {}
+    if not you:
+      you = next(
+        (snake for snake in api_snakes if snake["id"] == game_row["your_snake_id"]),
+        {},
+      )
+
+    turns.append({
+      "turn": turn,
+      "observed_at": row["observed_at"],
+      "my_move": row["my_move"],
+      "my_thinking": decode_json(row["my_thinking_json"]),
+      "board": board,
+      "food": food or [],
+      "hazards": hazards or [],
+      "you": you,
+      "snakes": snakes,
+    })
+
+  return turns