WasmVM: VFS missing POSIX filesystem hierarchy (/tmp, /bin, /etc, /var)

[NathanFlurry]

The os-test paths/ suite checks for standard POSIX filesystem hierarchy directories. Most fail because the VFS does not create them at startup.

Directories that should exist:

• /tmp, /var/tmp
• /bin, /usr/bin, /sbin, /usr/sbin
• /etc, /var, /usr, /lib
• /root (home for root user)

Device nodes already handled by the device layer (/dev/null, /dev/zero, /dev/stdin, /dev/stdout, /dev/stderr, /dev/urandom) pass exit 0 but some fail stdout parity (fixed by #31).

Directories that may remain unimplemented: /proc, /sys, /dev/console, /dev/full, /dev/tty, /dev/random, /dev/ptmx, /srv.

48 tests affected.

[NathanFlurry]

Fixed in d5c36187 — added /dev/random, /dev/tty, /dev/console, /dev/full to device layer and POSIX directory hierarchy to VFS. 45/48 paths tests pass (3 PTY tests remain excluded).