Single source of truth for the 18 RECON knowledge domains mapped to
PeerTube category IDs 100-117. Replaces duplicate VALID_DOMAINS sets
in enricher.py and embedder.py with imports from lib/recon_domains.py.
Includes PeerTube plugin (peertube-plugin-recon-domains) that registers
custom categories via videoCategoryManager.addConstant(), and a parity
test to verify constants match between RECON and the PeerTube API.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
