docs: per-process logging + the kernel VFS root

logging.md rewritten around the pipeline (std.log -> leveled debug_write
-> tagged ring -> logger service -> /var/log/<boot-stamp>/<binary-path>.log),
why the buffer is a kernel ring rather than a logging server (the
storage stack must log; early boot needs the buffer anyway), the
announce-once and counted-loss disciplines, and the accepted gaps.
vfs-protocol.md: the router is the kernel (fs_resolve names, backends
serve data); endpoint comes from resolve, not a registry lookup; mount/
unmount retired from the wire; the rewrite-prefix mount semantics.
vdso.md: klog_status + the fs naming calls join the future table; the
no-file-I/O line sharpened (kernel resolves names, never blocks on a
filesystem). syscall.md: the placeholder status blurb replaced with the
real call families.

docs/vdso.md

@@ -133,7 +133,8 @@ Grouped as `abi.zig` groups them:
 | ipc | `danos_endpoint_create`, `danos_ipc_register`, `danos_ipc_lookup`, `danos_ipc_call`, `danos_ipc_reply_wait`, `danos_ipc_send` |
 | devices | `danos_device_enumerate`, `danos_device_claim`, `danos_device_register`, `danos_mmio_map`, `danos_irq_bind`, `danos_irq_ack`, `danos_msi_bind`, `danos_io_read`, `danos_io_write` |
 | time | `danos_clock`, `danos_wall_clock`, `danos_timer_bind` |
-| diagnostics | `danos_debug_write`, `danos_klog_read` |
+| diagnostics | `danos_debug_write` (leveled, kernel-stamped records), `danos_klog_read`, `danos_klog_status` |
+| filesystem naming | `danos_fs_resolve`, `danos_fs_node`, `danos_fs_mount`, `danos_fs_unmount` (naming only — file DATA still crosses the vfs-protocol IPC, see below) |
 
 The constants that ride alongside the calls — mmap protection bits, DMA
 flags, notification badge bits, `ExitReason`, `Signal`, well-known service
@@ -197,8 +198,10 @@ Phased so every step ships alone (the M-milestone discipline):
   across processes stays what it is today: a service behind IPC, or source
   compiled into each binary.
 - **No file/device I/O in the vDSO.** The microkernel line doesn't move: the
-  vDSO wraps the same deliberately tiny table (docs/syscall.md); files are
-  still the VFS server's business over IPC.
+  vDSO wraps the same deliberately tiny table (docs/syscall.md). The kernel
+  resolves file NAMES (`fs_resolve` — the mount table moved in-kernel), but
+  file data is still the filesystem server's business over the vfs-protocol
+  IPC; the kernel never blocks on a userspace filesystem.
 - **No fast-path user-mode implementations yet.** Linux's vDSO exists mostly
   to answer `gettimeofday` without a kernel entry. `danos_clock` could one
   day read the calibrated TSC in user mode the same way — the blob is where