add page cache with read-ahead and dirty writeback, file-backed and anonymous mmap with CoW, VAD-based virtual memory replacing the old user region model, PFN database with eviction and reclaim, file identity for cross-open section sharing, FAT32 path cache and per-file cluster chain cache, serial.sys for COM1 keyboard input, xHCI MSI with INTx and polled fallback, PciEnableMsiAuto, waitable input queue, KeWaitForAnyEvent, per-process thread info syscall, expanded kernel stats (PFN/PTE/VAD/file-cache/disk), pool allocation tags, async I/O user buffer locking, file flush on close, add docs.md.

code/drivers/fs/fat32/fat32_mount.c

@@ -14,9 +14,11 @@ void Fat32InitVtable(IO_FILESYSTEM* fs, FAT32_VOL* vol) {
     fs->Delete     = Fat32Delete;
     fs->Truncate   = Fat32Truncate;
     fs->GetSize    = Fat32GetSize;
+    fs->QueryIdentity = Fat32QueryIdentity;
     fs->Close      = Fat32Close;
     fs->DriverCtx  = vol;
     fs->OpenDir    = Fat32OpenDir;
     fs->ReadDir    = Fat32ReadDir;
     fs->CloseDir   = Fat32CloseDir;
+    fs->QueryStats = Fat32QueryStats;
 }