docs: point at FCC internal photos for checking a PCB before opening it

[tuct]

fccid.io/2ARBY is Arovast Corporation — the entity behind Levoit/VeSync — and most of their filings include internal photos of the bare PCB.

That answers the "is it an ESP32 talking to a separate MCU?" question, shows the Wi-Fi module and often the test pads, before buying a device or taking one apart. The philips-900-series write-up already leaned on the MXCHIP filing this way; this generalises it.

Where it went

File	Why there
docs/adding-a-new-device.md	Step 1 is "open the unit and look at the PCB" — this is how you look first. Grantee table plus known IDs.
devices/README.md	Where models are browsed, next to the other general tips.
components/levoit/README.md	Right where disassembly is introduced.

Confirmed IDs

Device	FCC ID
Core 200S	2ARBY-CORE-200S
Core 300S	2ARBY-CORE-300S
Core 600S	2ARBY-CORE600S
Sprout	2ARBY-B381S
Dual 200S / OasisMist LV450S, LV600S	humidifiers, same grantee

Two traps documented

• The hyphenation is inconsistent — CORE-300S but CORE600S — so an ID can't be guessed from a model name. Browse the grantee index instead. I only listed IDs I verified; the rest are deliberately not guessed at.
• Internal photos are sometimes held under short-term confidentiality and appear late, and schematics/block diagrams are usually permanently confidential. Reconnaissance, not ground truth — and the photographed revision may not match the unit in hand.

🤖 Generated with Claude Code