Code Farm economy rebalance: market saturation, infrastructure/defense/cosmetics, mastery track, secondary leaderboards, admin eras, underdog bonus and weekly contracts

Every purchase/upgrade path (new and pre-existing) is now race-safe against concurrent requests via atomic conditional SQL updates.

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

devplacepy/utils/rewards.py

@@ -191,6 +191,10 @@ ACHIEVEMENTS = {
     "water": [(1, "Good Neighbor")],
     "harvest_stolen": [(1, "Cat Burglar")],
     "got_stolen_from": [(1, "Robbed")],
+    "infra_bought": [(1, "Enterprise Ready")],
+    "defense_upgraded": [(1, "Fort Knox")],
+    "cosmetic_bought": [(1, "Style Points")],
+    "underdog_raid": [(1, "David vs Goliath")],
 }
 
 UNIQUE_ACTIONS = {"docs.read"}