skill: add usb-sniffer — wire-level capture with the ataradov hardware tap

Fourth view in the USB debugging toolset (usbmon = host URBs, usb-debug =
host reasoning, usb-target-debug = device firmware, usb-sniffer = what
actually crossed D+/D-). Covers the ataradov/usb-sniffer analyzer:
headless pcapng capture (--speed ls/fs/hs, --fold, --limit self-exit),
Wireshark/tshark analysis recipes, and the wire realities that bite:
downstream broadcast, sniffer self-capture noise, xHCI devnum != wire
address, tap-point-dependent reset visibility (hub choreography anchors),
FS-behind-HS-hub splits. Every recipe hardware-validated on the rig,
including the capture-window floor (a 3 s window provably misses the
enumeration ladder; 3M packets minimum).

Two udev files with distinct audiences, not one:
- examples/device/99-tinyusb-examples.rules (renamed from 99-tinyusb.rules):
  the user-facing rules the examples need — cafe VID access, hidraw, the
  ModemManager blacklist, a couple of board probes. getting_started.rst,
  the webusb_serial README and its source comment point here.
- tools/88-tinyusb.rules: the HIL rig's private probe/analyzer allowlist,
  now with the sniffer (6666:6620 + blank FX2LP 04b4:8613). Installed on
  the rig only; the usb-sniffer skill references it.

1 files changed, 22 insertions, 0 deletions

diff --git a/examples/device/99-tinyusb-examples.rules b/examples/device/99-tinyusb-examples.rules
new file mode 100644
index 000000000..e7a399345
--- /dev/null
+++ b/examples/device/99-tinyusb-examples.rules
@@ -0,0 +1,22 @@
+# udev rules for running the TinyUSB device examples as a non-root user.
+# Copy this file to the location of your distribution's udev rules, for example on Ubuntu:
+#   sudo cp 99-tinyusb-examples.rules /etc/udev/rules.d/
+# Then reload udev configuration by executing:
+#   sudo udevadm control --reload-rules
+#   sudo udevadm trigger
+
+# Check SUBSYSTEM
+SUBSYSTEMS=="hidraw", KERNEL=="hidraw*", MODE="0666", GROUP="dialout"
+
+# Rule applies to all TinyUSB example
+ATTRS{idVendor}=="cafe", MODE="0666", GROUP="dialout"
+
+# Rule to blacklist TinyUSB example from being manipulated by ModemManager.
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="cafe", ENV{ID_MM_DEVICE_IGNORE}="1"
+
+# Xplained Pro SamG55 Device
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="03eb", ATTRS{idProduct}=="2111", MODE="0666", GROUP="users", ENV{ID_MM_DEVICE_IGNORE}="1"
+SUBSYSTEMS=="tty", ATTRS{idVendor}=="03eb", ATTRS{idProduct}=="2111", MODE="0666", GROUP="users", ENV{ID_MM_DEVICE_IGNORE}="1"
+
+# TI Stellaris/Tiva-C Launchpad ICDI
+SUBSYSTEM=="usb", ATTRS{idVendor}=="1cbe", ATTRS{idProduct}=="00fd", MODE="0666"