docs: refresh root documentation to reflect M1–M4 (current status, honest scope)

[STiFLeR7]

Summary

Brings every root-level document up to date and into a consistent, professional, current view. The root docs had drifted to a Phase 5 / 42-tests / "Phase 6 next" snapshot; they now reflect the true state: Phases 0–6 + Milestones M1–M4 all complete, the BYOM recovery library shipped, 141 tests, and the honest 0.x scope. No code changes — documentation only.

Per-file

• README.md — rewritten status arc (Phases → M1–M3 live NO-GO → M4 library); added a BYOM quick-start snippet + guide links; fixed badges (status, 141 passing, 0.x version); corrected the repository map (removed stale "benchmarks empty until Phase 5", added docs/guide/, BYOM example).
• ROADMAP.md — added M3 (powered live study, NO-GO) and M4 (BYOM library) to the milestone table + narrative + AP distribution.
• CHECKLIST.md — added M3 and M4 to the milestone rollup and their Action-Point + completion-criteria sections.
• REPRODUCE.md — 141-test count, added the BYOM example + expected output, and updated the live-runs section (M1–M3 complete, NO-GO; BYOM as the reproduce-it-yourself path).
• PAPER.md — §9 gains an M3 live-run entry and an M4 availability note; ADR range → ADR-0010; draft line notes currency through M4.
• ANNOUNCEMENT.md (gated v1.0 draft) — added the BYOM angle; honest-scope line now reflects the M1–M3 live attempts (suggestive, not confirmed).

Deliberately unchanged

• CHANGELOG.md — historical [0.2.0]/M2 entries kept verbatim (point-in-time by design); the M4 [Unreleased] section already landed in AP-5.
• CONTRIBUTING.md, CODE_OF_CONDUCT.md — evergreen, no stale facts.
• CHECKLIST per-phase "N tests passing" notes kept (they record the count at each phase's close, not the current total).

Governance

• No src/ or behavior change — docs only; suite still 141 passed.
• Honest scope preserved throughout: C1 not confirmed; stays 0.x; no publish/release/announce (ANNOUNCEMENT remains a gated draft).

Test Plan

• python -m pytest -q → 141 passed.
• No stale status/test figures remain in live surfaces (verified by grep; only legitimate historical records left).
• Maintainer review + merge (yours).

🤖 Generated with Claude Code

[STiFLeR7]

Maintainer review — APPROVED for merge ✅

Docs-only refresh; verified accurate and consistent.

• Root docs now reflect the true state: Phases 0–6 + M1–M4 complete, BYOM library shipped, 141 tests, honest 0.x scope.
• No src/ or behavior change — suite still 141 passed.
• Historical records (CHANGELOG [0.2.0], per-phase test-count notes) correctly left intact; live status surfaces fully current.
• Honest scope preserved: C1 not confirmed, stays 0.x, ANNOUNCEMENT remains a gated draft.

MERGEABLE / CLEAN. Merging — this makes the docs accurate ahead of the v0.3.0 milestone tag.