README: refactor for Phases 0-5 self-evolution + accessibility pass

- Add a "Self-evolving verifier" section as a first-class concept,
  documenting how five validated insights from the engine's own
  ideation_on_ideation journal became phases of the verifier itself
  (canonicalization + alias-gap, three-stage refactor,
  component-resolved novelty, Pareto admission, explore/verify
  space split).
- Add the new diagnostic CLIs: --three-stage-test, --pareto-frontier,
  --pareto-admission-test, --backfill-canonical-forms /
  --backfill-force.
- Update the pipeline diagram to show the three-stage verifier with
  STRICT short-circuit and BAND priming branches, the explore/verify
  separation in the investigation loop, and the Pareto admission
  outcome of the register gate.
- Expand configuration to document register_admission_mode (scalar
  vs pareto) and investigation_assessor_role.
- Update register UI description to mention per-component novelty
  badges and the alias-against banner.
- Plain-language "What it actually does" section up front so a
  non-specialist reader gets the shape before the jargon.
- Cut the alphabet-soup roadmap, the redundant Provenance section,
  the iterative-workflow subsection (redundant with the quickstart),
  and the migration-from-pre-Docker note. Trim "Honest limitations"
  to its substantive points.
- Soften technical-briefing language: introduce structural-novelty
  framing in plain terms before the formal premises_supported /
  synthesis_findable axes; rename "Honest limitations" entries to
  describe failure modes in plain language.
- Net: 690 → 539 lines, more coverage, less filler.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: sfw