README: rewrite landing page to reflect actual state of project

The previous README was a build receipt from Phase 1 — it sold a
544KB native binary and "50-100× faster than Python" with no
benchmark behind it, and made no mention of the eleven phases
(V.6 → V.9b → H.1 → H.4) that closed the self-hosting loop and
built the self-healing compiler.

This rewrite leads with what's actually here now and verifiable
on the binary in this repo:

  - Two-track framing: PL researchers and developers each get
    an upfront pitch keyed to their concerns.
  - "What's proven right now" table with file paths the reader
    can run today to verify each architectural claim.
  - "The arc" as the narrative spine — V.1 through H.4, each
    phase a real artifact in examples/, not a roadmap item.
  - Quick start with three headline demo commands.
  - "What this doesn't do yet" section: naive brace placement,
    unexercised stuck/exhausted outcomes, no fast bytecode runtime,
    no LSP/formatter/debugger, single-developer experiment, no
    external review. Honest in detail, confident at the top.
  - Implications section connecting the architectural pattern to
    LLM-generated code specifically.

All file paths cited in the README were verified to exist; the
self_hosting_v9b.omc headline was re-run before commit and still
produces ✓✓✓ ALL THREE FIXPOINTS REACHED.

The previous README's content about quick start, examples, and
build instructions is preserved in updated form. Architecture
deep-dive and milestone history continue to live in their
dedicated docs (ARCHITECTURE.md, CHANGELOG.md).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: RandomCoder-lab