Audience role label and lede orientation

Clarified the Audience / POV writing gate:

  • Lead-table label is Audience role (page-audience attr unchanged; needs @antora-supplemental/page-context 0.6.2+).

  • Value = the necessary role (permissions / access / usage expectations) — Developer ≠ User, Admin ≠ Member — not task padding.

  • Surface/channel stays in page-usage-context; task orientation belongs in the lede.

  • Lede must orient without the Audience role table (humans skip chrome).

  • Updated general/documentation.md, user.md, agents/editorial/titles.md, agents/engineering/antora.md, general/global.md, and skills antora-org-site, writing-blog, writing-news.