Add a PSP Firmware screen under Settings > Tools

Shows what's actually in PSP/NAND - nothing, a fonts-only partial install, or
a full firmware with its version, build date and region - read from
flash0:/vsh/etc/version.txt, which is present both in a PSAR-unpacked install
and a NAND dumped off hardware.

Also offers to install an updater, erase the NAND, and launch the XMB, the
last one gated on FirmwareVersionSupportsVSH() since the module patches that
get vshmain.prx running are tied to 6.61's offsets.

Installing a firmware now erases flash0/flash1/ipl first - two firmwares can't
be merged, a file the new one doesn't have would linger and still get loaded.

Co-Authored-By: Claude Opus 5 <[email protected]>

UI/MainScreen.cpp

@@ -101,7 +101,7 @@ static void LaunchFile(ScreenManager *screenManager, Screen *currentScreen, cons
 				std::string title = info->GetTitle();  // includes the version.
 				// The unpacker wants the PBP itself, not the folder it happens to sit in.
 				const Path pbpPath = info->fileType == IdentifiedFileType::PSP_PBP ? path : path / "EBOOT.PBP";
-				screenManager->push(new InstallUpdateScreen(pbpPath, title));
+				screenManager->push(new InstallUpdateScreen(pbpPath, title, true));
 				return;
 			}
 			break;