Add tests for PatchSet and ServeSession functionality

- Introduced comprehensive tests for the `PatchSet` module, covering methods such as `hasRemoves`, `hasAdditions`, `hasUpdates`, and various ID and instance checks.
- Added a new test suite for `ServeSession`, focusing on WebSocket message handling and confirmation behavior, ensuring correct merging and application of patches.
- Implemented edge case tests in `ChangeBatcher` to verify data integrity during rapid changes and instance removals.
- Enhanced `applyPatch` tests to handle scenarios involving missing instances and ignored class names, ensuring robust patch application logic.

plugin/src/ServeSession.lua

@@ -230,7 +230,7 @@ function ServeSession:__onWebSocketMessage(messagesPacket)
 	-- If we're already waiting for confirmation, merge into the patch being confirmed
 	-- Changes flow into the dialogue even in one-shot mode so user can see them
 	if self.__confirmingPatch ~= nil then
-		Log.trace("Already confirming, merging into current patch")
+		Log.info("Already confirming, merging into current patch")
 
 		-- Collect IDs of items that are being changed (for unselecting in UI)
 		local changedIds = {}
@@ -291,7 +291,10 @@ function ServeSession:__onWebSocketMessage(messagesPacket)
 			-- that arrived while we were waiting for confirmation
 			self:__applyPatch(combinedPatch)
 		end
-		-- Note: "Reject" is not handled for ongoing patches, only for initial sync
+		-- Note: Table-type responses ({ type = "Confirm", selections = ... }) from
+		-- the selection-based UI are not yet handled here. Ongoing WebSocket patches
+		-- with per-item selections would need the same logic as
+		-- __confirmAndApplyInitialPatch to properly respect push/pull/ignore choices.
 	end)
 
 	self.__apiContext:setMessageCursor(messagesPacket.messageCursor)