Palette Swap for MineColonies

Fixed

• Multiplayer (dedicated servers) now works — the active substitution ruleset is synced server → client on join and after /reload, so the build-wand preview and the Replace picker work on remote servers (they previously only worked in single-player, where client and server share the loaded rules).
• Stale picks after rejoining — replacement choices are now cleared on disconnect, so after rejoining a server the preview no longer shows substitutions that placement wouldn't apply.
• Duplicate Replace button — the shape tool no longer stacks an extra Replace button each time its block picker is used.
• Network hardening — malformed/hostile packets with absurd element counts are now rejected at decode instead of forcing huge allocations (could crash a server or client), and the choices message only accepts the client → server direction.
• Stale palette adoption — picks staged at structure placement now expire after a short window and are scoped to the dimension (and cleared on server stop), so a hut placed at the same coordinates in another dimension or a later single-player world no longer silently adopts an old palette.
• /reload with tag rules — from_tag rule matches are no longer cached against the pre-reload tag contents during the brief window before tags rebind.
• Deterministic rule conflicts — equal-priority rules for the same source block from different datapack files now resolve in a stable (sorted file id) order instead of an arbitrary one. To override a rule from another pack, give yours a higher "priority".
• Malformed rule files — a broken entry mid-file now skips the whole file (as the log always claimed) instead of keeping the entries parsed before the error.