bug pass: whole console lines, a quiet SCI, an honest reserve warning

- schinit, schinitd and vgpud build every message from pieces, one
  write() each, so a job starting on another CPU landed mid-line:
  "schinitd: starting vgpud: os.schos.resolvconfno virtio-gpu on this
  machine". They now collect a line and write it at the newline;
  resolvconf's verbose line is one write with its prefix.
- The ACPI SCI registers IRQ_QUIET. A desktop's SCI never fires, and the
  poller took two seconds of silence for a misrouted line ("irq 9:
  nothing has arrived on it") and called the handler every tick. A line
  is only exempt while every handler on it is quiet.
- The loader claims each segment from where the last one's claim ended,
  so two segments sharing a page no longer ask for it twice. When a
  claim is still refused, it names the memory-map entries in the way.
- Stale divesymlink() declaration gone; the kernel.md struct table
  re-measured (inode, buf and file pools grow from slabs now).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4

kernel/acpi/host.c

@@ -501,7 +501,7 @@ uacpi_kernel_install_interrupt_handler(uacpi_u32 irq,
   s->fn = fn;
   s->ctx = ctx;
   s->irq = gsi;
-  if (irq_register(gsi, sci_trampoline, s, "acpi", mode) < 0) {
+  if (irq_register(gsi, sci_trampoline, s, "acpi", mode | IRQ_QUIET) < 0) {
     uacpi_kernel_free(s);
     return UACPI_STATUS_INTERNAL_ERROR;
   }