docs: add profile integration plan and beads for epistemic spine

Define the full profile integration design for rvl matching shape's
level of detail: CLI flags, key precedence, column scoping, JSON/human
output changes, witness params, and three new refusal codes. Corrects
shape's E_AMBIGUOUS_PROFILE mistake (domain refusal, not clap conflict).

Beads: bd-290, bd-2v8, bd-2g3, bd-1tq, bd-cmy, bd-2j5, bd-14u, bd-148, bd-2h7

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: saltmachine