feat: server-synced bag sort, fix world map continent bounds, update docs

Inventory sort: clicking "Sort Bags" now generates CMSG_SWAP_ITEM packets
to move items server-side (one swap per frame to avoid race conditions).
Client-side sort runs immediately for visual preview; server swaps follow.
New Inventory::computeSortSwaps() computes minimal swap sequence using
selection-sort permutation on quality→itemId→stackCount comparator.

World map: fix continent bounds derivation that used intersection (max/min)
instead of union (min/max) of child zone bounds, causing continent views
to display zoomed-in/clipped.

Update README.md and docs/status.md with current features, release info,
and known gaps (v1.8.2-preview, 664 opcode handlers, NPC voices, bag
independence, CharSections auto-detect, quest GO server limitation).

include/ui/inventory_screen.hpp

@@ -6,6 +6,7 @@
 #include <vulkan/vulkan.h>
 #include <imgui.h>
 #include <array>
+#include <deque>
 #include <functional>
 #include <memory>
 #include <unordered_map>
@@ -195,6 +196,9 @@ private:
     int splitCount_ = 1;
     std::string splitItemName_;
 
+    // Server-side bag sort swap queue (one swap per frame)
+    std::deque<game::Inventory::SwapOp> sortSwapQueue_;
+
     // Pending chat item link from shift-click
     std::string pendingChatItemLink_;