API: in-process boti ako hraci

Boti su sedadla bez socketu: ucty bot:<kind>-<n> v tabulke players
(nehijacknutelne, recyklovane medzi hrami), handlery add_bot/remove_bot
(len hostitel, pred startom) a tahova slucka _run_bot_turns s pauzou
BOT_MOVE_DELAY_SECONDS a MC/inferenciou v executori. Druhy: heuristic,
random, neural (pure-Python siet; bez suboru vah jasna chyba a pri
restore fallback na heuristiku). Botie sedadla preziju restart servera.

Oprava po ceste: emit kariet hracovi so sid=None (offline sedadlo po
restore) broadcastoval jeho karty vsetkym klientom -- preskakuje sa.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.dockerignore

@@ -10,3 +10,6 @@ frontend
 .env
 .env.*
 docker-compose*.yaml
+# trenovacie artefakty do image nepatria (produkcia cita len rl/weights/)
+rl/checkpoints
+rl/runs