feat(registry): compile vim from source; audit fixes (http_get wired, make package deleted)

[NathanFlurry]

• vim now compiles from source: make -C registry/native cmd/vim clones the pinned v9.2.0780, builds the termios/termcap/POSIX bridge in registry/native/c/vim/ (including a recreated musl-layout termios.h — wasi-libc ships none), cross-configures with a generated compiler wrapper, and produces the 2.8 MB wasm binary — the hand-built drop-zone flow is dead for vim (vix remains the only external binary)
• Registry automation audit fixes: http_get wired into C_COMMANDS and the C bulk COMMANDS list (source existed, was never opted in); the make package deleted — a stub with no build path anywhere, with all references removed (build-essential, core test-runtime command tiers)
• just registry-build uses --force (turbo's cache can't see the native commands dir, so cached replays shipped stale staging)
• Validated: source-built vim runs in the VM (correct version banner; scripted insert + :wq writes the file byte-exact)