tool migration: v2 exports + 10 external CLI binaries

rsapi v2: 14 new ABI function pointers appended after v1 — fs_resolve,
fs_dir_next (iterator), fs_create, fs_remove, fs_read, fs_write,
fs_size, fs_close, rtc_now, mem_stats, pci_probe, pci_device,
klog_dump, kernel_version.  New C-repr structs: DirEntry, RtcTime,
MemStats, PciDevice, KernelVersion.  ABI_VERSION bumped to 2.

Shell-side: build_exports() constructs the full table at runtime per
invocation (replaces static const).  14 kernel-side wrapper functions
bridge rsapi types to rsnix kernel APIs; fs_dir_next maintains a
per-handle cache of children() results for iteration.

Tool binaries (10 crates, all linked against rsapi only):
- date: rtc_now → formatted YYYY-MM-DD HH:MM:SS
- mem: heap/pages free/total via mem_stats
- pci: pci_probe + pci_device enumerate all devices
- cat: fs_read paths or get_line stdin; put_line output
- ls: fs_resolve + fs_dir_next iteration; trailing / for dirs
- mkdir: fs_create(path, true)
- touch: fs_create(path, false)
- rm: fs_remove(path)
- klog: klog_dump 2048 bytes → put_line
- info: rtc_now + kernel_version (minimal; mem/pci deferred)

Gate verified: date prints RTC; pci lists all 4 QEMU devices
(8086:29c0, 1234:1111, 8086:10d3, 8086:2918); hello/boom/count
still work; test-disk PASS; poweroff clean.

1 files changed, 70 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 0ca76eb..35ac614 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10,6 +10,13 @@ dependencies = [
 ]
 
 [[package]]
+name = "cat"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
 name = "count"
 version = "0.6.0"
 dependencies = [
@@ -17,6 +24,13 @@ dependencies = [
 ]
 
 [[package]]
+name = "date"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
 name = "hello"
 version = "0.6.0"
 dependencies = [
@@ -24,6 +38,55 @@ dependencies = [
 ]
 
 [[package]]
+name = "info"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "klog"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "ls"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "mem"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "mkdir"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "pci"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
+name = "rm"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]
+
+[[package]]
 name = "rsapi"
 version = "0.6.0"
 
@@ -65,3 +128,10 @@ dependencies = [
  "rsnix",
  "rspaint",
 ]
+
+[[package]]
+name = "touch"
+version = "0.6.0"
+dependencies = [
+ "rsapi",
+]