Changelogs: add 5.2 and 5.3

Author: greenrobot

docs/README.mdx

@@ -68,6 +68,41 @@ Otherwise, feel free to open an issue on [GitHub ](https://github.com/objectbox/
 
 <div align="left"><img src="https://img.shields.io/github/v/release/objectbox/objectbox-c?style=for-the-badge" alt=""/></div>
 
+5.3.0 (2026-03-23)
+------------------
+* Change log level at runtime, i.e. `obx_log_level_set()`/`obx_log_level_get()`
+* New log level "trace" for most internal details
+* Log level "verbose" can now be enabled (debug log builds only)
+* **Breaking:** `OBXLogLevel` enum values changed; recompile with new header if you used these
+(previously 10/20/30/40/50 for Verbose..Error, now 0-10 matching the runtime log level).
+* Admin: Status tab "Count and Sizes" now only counts all objects on click to preserve resources
+* Admin: Status tab "Count and Sizes" now has a sum row at the bottom
+* Admin: Status tab "System and Info" now shows additional information
+* Process memory / RSS
+* Database size and free disk size
+* CPU counts and loads
+
+### Sync
+
+* Conflict resolution via sync clock and sync precedence (allows last win with custom conflict resolution)
+* Fix bad Sync client state after multiple full sync messages were interrupted
+* Fix adding indexes to Sync types
+
+5.2.0 (2026-03-06)
+------------------
+* Admin: new "Counts and Sizes" view (via Status page) to give an overview over all types their object counts and sizes
+* Admin: refresh button for the data view
+* Admin: fix reload via browser to stay on the page
+* Admin: schema view to display flags as text
+* (Minor) performance improvements of HNSW vector search on Linux ARM targets
+
+### Sync
+
+* Sync protocol version 10
+* Update client sync filters variables when online
+* Clients report errors to the server
+* Add OBXSyncFlags_SkipInvalidTxOps
+
 ### 5.1.0 (2026-01-19)
 
 * Fix for deleting transactions in non-owner threads with open relation cursors