Phase 37.1: Fix STDIN routing (compositor bypass)

Issue: NipBox was blocking on READ syscall forever.
Root Cause: Input was being routed to inactive compositor channel.

Fix: Route stdin directly to chan_input since compositor is not operational in Phase 37.

Status:
- ✅ STDIN routing path corrected
- ⚠️ UART input still not reaching NexShell (polling issue or timing)

Next: Investigate UART ISR or add buffering for pre-boot input.

core/kernel.nim

@@ -149,12 +149,8 @@ proc ion_push_stdin*(p: pointer, len: csize_t) {.exportc, cdecl.} =
 
   kprintln("[Kernel] Input packet pushed to ring")
 
-  # Phase 35d: Route to Compositor FIRST
-  if chan_compositor_input.ring != nil:
-    chan_compositor_input.send(pkt)
-  else:
-    # Fallback to direct routing if compositor not active
-    chan_input.send(pkt)
+  # Phase 37: Direct routing (Compositor not yet operational)
+  chan_input.send(pkt)
 
 proc get_ion_load(): int =
   ## Calculate load of the Command Ring (The Heartbeat of the NPLs)