step 6: add stable overlays and live update stress tests

README.md

@@ -2,7 +2,7 @@
 
 `dpg-map` is a Dear PyGui map widget package under rebuild.
 
-The Step 5 interaction layer is in place:
+The Step 6 overlay rendering layer is in place:
 
 ```python
 import dpg_map as dpgm
@@ -36,9 +36,8 @@ Implemented so far:
 - memory cache with visible-tile protection and GUI-thread texture deletion
 - measured-rectangle mouse interaction for left-drag panning and wheel zooming
 - programmatic view commands and screen/latitude-longitude conversion helpers
-
-Overlay drawing is not implemented yet. Step 6 will add overlay rendering and
-live update stress examples.
+- marker, polyline, and trajectory rendering on a draw layer separate from tiles
+- background-thread overlay updates that coalesce without resetting center or zoom
 
 Examples:
 
@@ -49,4 +48,6 @@ uv run python examples/sizing_child.py
 uv run python examples/sizing_table.py
 uv run python examples/hidden_tab.py
 uv run python examples/cache_stress.py
+uv run python examples/markers_live_thread.py
+uv run python examples/trajectory_live_thread.py
 ```