refactor: extract dispatch dict and _handle_reaction in _handle_message() (closes #451)

[mholzi]

Fixes #451 — refactors the 252-line _handle_message() into a dispatch dict pattern and extracts _handle_reaction(), removing PLR0912/PLR0915 noqa suppressions.

[gemini-code-assist]

Code Review

This pull request refactors the WebSocket message handling in custom_components/beatify/server/websocket.py by replacing a large conditional block with a dispatch dictionary and dedicated handler methods. This change improves code organization and reduces method complexity. The review feedback suggests utilizing the existing get_player_by_ws helper method in the admin handler to replace a manual iteration, enhancing code efficiency and consistency.

[gemini-code-assist]

The manual iteration to find the player session by WebSocket can be replaced with the more efficient game_state.get_player_by_ws(ws) method. This improves readability and leverages the existing API already used in other handlers like _handle_reaction.

Suggested change

	sender = None
	for player in list(game_state.players.values()):
	if player.ws == ws:
	sender = player
	break
	sender = game_state.get_player_by_ws(ws)

[mholzi]

Self-review: LGTM — clean refactor.

Dispatch dict: all 11 original if/elif branches correctly mapped; unknown types still log a warning.

Extracted methods: _handle_reaction(), _handle_join(), _handle_admin(), _handle_get_state() all preserve original logic exactly. Signatures are consistent with existing handler patterns (ws, data, game_state).

Signature normalization: _handle_leave and _handle_get_steal_targets correctly gained the unused data param for uniform dispatch — confirmed no other callers exist.

noqa cleanup: PLR0912/PLR0915 suppressions removed as expected.

No regressions, edge cases, or correctness issues found.