feat(rumpk): Sovereign Core enhancements - NexShell IPC hardening & NipBox utility expansion

- Improved NexShell signal integrity by consolidating ION packet transmission.
- Added 'ls' and enhanced 'matrix' control to NipBox (Sovereign Coreutils).
- Added emergency matrix override to NexShell kernel mode.
- Fixed 'command not found' errors caused by IPC fragmentation.

nipbox.nim

@@ -0,0 +1,89 @@
+# src/npl/nipbox/nipbox.nim
+import std/[strutils, tables]
+
+# --- COMMANDS ---
+
+proc do_echo(args: seq[string]) =
+  echo args.join(" ")
+
+proc do_ls(args: seq[string]) =
+  # A Sovereign 'ls' - eventually this will query the NPL filesystem
+  echo ".          .."
+  echo "kernel     subject"
+  echo "matrix     ion"
+  echo "vault      pki"
+
+const CMD_GPU_MATRIX = 0x100
+const CMD_GPU_CLEAR = 0x101
+
+proc nexus_syscall(cmd: uint32, arg: uint32): cint {.importc, cdecl.}
+
+proc do_matrix(args: seq[string]) =
+  let enable = if args.len > 0 and args[0] == "off": 0'u32 else: 1'u32
+  let state = if enable == 1: "ON" else: "OFF"
+  echo "[NipBox] Matrix Protocol: Setting state to " & state
+  if nexus_syscall(CMD_GPU_MATRIX, enable) != 0:
+    echo "[Error] Command Ring Full!"
+  else:
+    echo "[NipBox] Command Sent Successfully."
+
+proc do_help(args: seq[string]) =
+  echo "NipBox v0.1 (Sovereign Coreutils)"
+  echo "  echo [args...] : Print arguments"
+  echo "  ls             : List sovereign objects"
+  echo "  matrix [on/off]: Toggle visualizer"
+  echo "  help           : Show this message"
+  echo "  version        : Show version info"
+
+proc do_version(args: seq[string]) =
+  echo "NipBox v0.1.0"
+  echo "Built: 2025-12-31"
+  echo "Architect: Markus Maiwald | Voxis Forge (AI)"
+
+const CMD_GET_GPU_STATUS = 0x102
+
+proc do_status(args: seq[string]) =
+  echo "[NipBox] Querying GPU Status..."
+  let status = nexus_syscall(CMD_GET_GPU_STATUS, 0)
+  echo "GPU Status: ", if status == 1: "ONLINE (Retina Active)" else: "OFFLINE"
+
+# --- DISPATCHER ---
+
+const commands = {
+  "echo": do_echo,
+  "ls": do_ls,
+  "matrix": do_matrix,
+  "status": do_status,
+  "help": do_help,
+  "version": do_version
+}.toTable
+
+proc main() =
+  proc nexus_yield() {.importc, cdecl.}
+  echo "\n[NipBox] Shell Ready. Waiting for orders..."
+
+  while true:
+    stdout.write("root@nexus:# ")
+    stdout.flushFile()
+
+    let line = try: stdin.readLine() except: ""
+
+    if line.len == 0:
+      nexus_yield()
+      continue
+
+    let parts = line.split(' ')
+    if parts.len == 0: continue
+    let cmd = parts[0]
+    let args = if parts.len > 1: parts[1..^1] else: @[]
+
+    if commands.hasKey(cmd):
+      commands[cmd](args)
+    elif cmd == "exit":
+      echo "[NipBox] Dropping to Kernel View..."
+      break
+    else:
+      echo "nipbox: command not found: ", cmd
+
+when isMainModule:
+  main()