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, 53 insertions, 0 deletions

diff --git a/bins/pci/src/main.rs b/bins/pci/src/main.rs
new file mode 100644
index 0000000..1182d83
--- /dev/null
+++ b/bins/pci/src/main.rs
@@ -0,0 +1,53 @@
+//! pci — list PCI devices via the exports table.
+
+#![no_std]
+#![no_main]
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    loop { core::hint::spin_loop(); }
+}
+
+fn put(exports: &rsapi::Exports, buf: &[u8]) {
+    (exports.put_line)(rsapi::Line { ptr: buf.as_ptr(), len: buf.len() });
+}
+
+fn hex2(b: u8, out: &mut [u8]) {
+    let hi = b >> 4; let lo = b & 0xf;
+    out[0] = if hi < 10 { b'0' + hi } else { b'a' + hi - 10 };
+    out[1] = if lo < 10 { b'0' + lo } else { b'a' + lo - 10 };
+}
+
+#[unsafe(no_mangle)]
+pub extern "C" fn efi_main(exports: &'static rsapi::Exports, _argc: usize, _argv: *const rsapi::Arg) -> i32 {
+    let count = (exports.pci_probe)();
+    let mut i = 0u32;
+    while i < count {
+        let mut d = rsapi::PciDevice { bus: 0, device: 0, function: 0, class: 0, subclass: 0, vendor: 0, device_id: 0 };
+        if (exports.pci_device)(i, &mut d) {
+            // "XX:XX.F class=XX:XX ven=XXXX dev=XXXX" = 42 bytes max
+            let mut buf = [0u8; 42];
+            hex2(d.bus, &mut buf[0..2]); buf[2] = b':';
+            hex2(d.device, &mut buf[3..5]); buf[5] = b'.';
+            buf[6] = b'0' + d.function;
+            let class_lbl = b" class=";
+            buf[7..7+class_lbl.len()].copy_from_slice(class_lbl);
+            let o = 7 + class_lbl.len();
+            hex2(d.class, &mut buf[o..o+2]); buf[o+2] = b':';
+            hex2(d.subclass, &mut buf[o+3..o+5]);
+            let ven_lbl = b" ven=";
+            buf[o+5..o+5+ven_lbl.len()].copy_from_slice(ven_lbl);
+            let v = o + 5 + ven_lbl.len();
+            hex2((d.vendor >> 8) as u8, &mut buf[v..v+2]);
+            hex2((d.vendor & 0xff) as u8, &mut buf[v+2..v+4]);
+            let dev_lbl = b" dev=";
+            buf[v+4..v+4+dev_lbl.len()].copy_from_slice(dev_lbl);
+            let dd = v + 4 + dev_lbl.len();
+            hex2((d.device_id >> 8) as u8, &mut buf[dd..dd+2]);
+            hex2((d.device_id & 0xff) as u8, &mut buf[dd+2..dd+4]);
+            put(exports, &buf[..dd+4]);
+        }
+        i += 1;
+    }
+    0
+}