docs: add read-doc skill, tighten CLAUDE.md and skill docs (#3778)HEADmaster

* docs: add read-doc skill for on-demand datasheet lookup

Search and read MCU datasheets, reference manuals, errata, and the USB
spec from a local Calibre library ($HOME/Documents/calibre-library)
instead of answering register/bitfield/pinout questions from model
memory. Gated on the library's existence, so it no-ops for contributors
who don't have it.

* docs: reference read-doc skill and tighten CLAUDE.md

Point the datasheet/reference entry at the new read-doc skill, and trim
sections that only duplicate a skill already owning the detail:
PVS-Studio and Code Size collapse to pointers; GDB/Build/Flash command
blocks condensed to essentials. 213 -> 129 lines; behavioral guidelines
and the validation checklist unchanged.

* docs: tighten skill redundancy; rename AGENTS.md refs to CLAUDE.md

code-size: fold the step list into a sentence and drop invocation
examples the argument tables already cover. hil: merge the duplicated
self-lock bullets and compress the hifiphile note. usbmon: compress the
group-membership setup paragraph. All commands, flags, lock rules, and
report paths preserved. usb-target-debug and the pvs script only get
stale AGENTS.md references renamed to CLAUDE.md (now the real file);
run_pvs.sh no longer cites a --dump-files mention that CLAUDE.md dropped.

* docs: fix review findings — restore Espressif cd step, ELF placeholder, code-size comment

Codex/Copilot/Claude review of #3778: the condensed Espressif bullet
lost its cd (idf.py resolves the project from CWD, so the command failed
from repo root); the GDB example now uses the build/your_app.elf
placeholder that docs/troubleshooting.rst established; the code-size
invocation comment no longer references --combined, which the shown
command doesn't use.

1 files changed, 1 insertions, 3 deletions

diff --git a/.claude/skills/usbmon/SKILL.md b/.claude/skills/usbmon/SKILL.md
index 4164dcf2e..85ec33248 100644
--- a/.claude/skills/usbmon/SKILL.md
+++ b/.claude/skills/usbmon/SKILL.md
@@ -7,9 +7,7 @@ description: Use when capturing, analyzing, or debugging USB bus traffic for Tin
 
 `usbmon` records host-side **URBs** — control / bulk / interrupt / isochronous transfers, descriptors, class requests, STALLs, short packets — i.e. exactly what the host exchanged with a device. Use it to debug a TinyUSB device on real hardware. (It's host/URB-level, not wire-level; for SOF/ACK/electrical use a hardware analyzer.)
 
-**Setup (assumed in place):** `usbmon` loaded and a udev rule `SUBSYSTEM=="usbmon", GROUP="wireshark", MODE="0640"` with your user in the `wireshark` group — so `tshark` captures with no `sudo`.
-
-If you were just added to `wireshark` (e.g. `usermod -aG`), the running shell/agent still has the old group set (group adds only apply to a fresh login). Don't restart — wrap each capture in `sg wireshark -c '…'`, which re-reads `/etc/group` immediately: `sg wireshark -c 'tshark -i usbmon3 -s 128 -a duration:30 -w /tmp/cap.pcapng'`. (Reading a finished `.pcapng` with `tshark -r` needs no special group.) For long/high-throughput captures add `-s 128` (snaplen) to keep only URB headers/status, not payloads.
+**Setup (assumed in place):** `usbmon` loaded and a udev rule `SUBSYSTEM=="usbmon", GROUP="wireshark", MODE="0640"` with your user in the `wireshark` group — so `tshark` captures with no `sudo`. Freshly added to the group? The running shell doesn't have it yet (group adds need a new login) — wrap captures in `sg wireshark -c 'tshark -i usbmon3 -s 128 -a duration:30 -w /tmp/cap.pcapng'`; reading a finished `.pcapng` (`tshark -r`) needs no group. `-s 128` (snaplen) keeps only URB headers/status, not payloads — use it for long/high-throughput captures.
 
 ## Capture