ImDebugger: Fix the memory window stealing keys, and keys stuck after closing

The memory window's single-letter shortcuts (F, B, H, U...) were taken even
when it wasn't focused, opening the search form and focusing its text field
while the game had the keyboard. Only take them when the window is focused,
like the disassembly window does.

Key events don't reach imgui while the debugger is hidden, so a key held while
closing it stayed down. Clear imgui's key state while it's hidden.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

UI/ImDebugger/ImMemView.cpp

@@ -1218,8 +1218,10 @@ void ImMemWindow::Draw(MIPSDebugInterface *mipsDebug, ImConfig &cfg, ImControl &
 
 	StatusBar(memView_.StatusMessage());
 
+	// These are single letters, so only take them when this window has focus, or they'd be stolen from the game.
+	const bool focused = ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows);
 	ImGui::End();
-	if (!ImGui::GetIO().WantTextInput) {
+	if (focused && !ImGui::GetIO().WantTextInput) {
 		ProcessKeyboardShortcuts();
 	}
 }

UI/NativeApp.cpp

@@ -446,6 +446,8 @@ void runImDebugger(Draw::DrawContext *draw) {
 		SetOverrideScreenFrame(nullptr);
 		if (imDebugger_) {
 			imDebugger_->OnHidden();
+			// Key events don't reach imgui while it's hidden, so it would miss the release of a key held when it closed.
+			ImGui::GetIO().ClearInputKeys();
 		}
 	}