Run library, checks and downloads in background threads with parallel fetching

CHANGELOG.md

@@ -1,5 +1,30 @@
 # Changelog
 
+## [1.2.0] — 2026-06-06
+
+### Features
+
+- Background threading — library refresh, update checks and downloads now run off the GUI thread, so the app no longer freezes during network or disk I/O
+- Parallel product-info fetching — up to 16 concurrent requests dramatically speed up library refresh and update checks (previously one request per game, sequentially)
+- Download progress — per-file byte progress bar with live transfer speed, plus a Cancel button to abort an in-progress download
+
+### Improvements
+
+- "Scan Existing Installers" now matches sanitized folder names and marks detected games as managed, so they appear checked in the Library tab
+- In-session caching of product info and owned game IDs in the GOG API client, cleared at the start of each manual refresh
+- Atomic writes for `config.json`, metadata and auth tokens — a crash mid-write can no longer corrupt them
+- `User-Agent` header now reports the real application version
+- File logging to `~/.config/gogupdater/gogupdater.log` (2 MB rotation) plus verbose diagnostics and logging of uncaught exceptions raised inside Qt slots
+
+### Fixes
+
+- Background workers were garbage-collected before running, so "Refresh Library" and "Check for Updates" did nothing — workers are now kept alive until their thread finishes
+- Download resume no longer corrupts files when the server ignores the HTTP `Range` request (falls back to a full re-download)
+
+### Tests
+
+- Added unit tests for folder-name sanitization, version comparison, prune strategies, atomic writes and the threading helpers; rewrote the stale constants test to match the current module
+
 ## [1.1.0] — 2026-05-13
 
 ### Features