docs: align documentation for v2.0.0-rc.1

[RedEyeNinja-BKK]

Docs-only: align documentation for v2.0.0-rc.1

Pre-Release Documentation Alignment Gate. Documentation only - no product code, tests, CI, package version (2.0.0rc1), or CLI surface changes.

What changed

• README.md - rewritten as the primary new-user entry point: what/why, RC1 scope (implemented vs intentionally-not-in-RC1), persistence story, migrate/export how-to, supported Python/CLI, concise validation summary, and a vertical mermaid diagram of the Method Factory spine (Intent → Collect → Clarify → Objective → Summary Gate → Pattern Author → Review → Trial → Ship → Triage).
• docs/public-surface.md - removed stale current-facing "Phase 2 foundation closure" header and the "PR draft: reset Method Factory canonical persistence to SQLite #1 Draft, v2.0.0a1" note (first release is v2.0.0-rc.1).
• docs/adr/ADR-0012 - status corrected from "implementation pending" to "released as v2.0.0-rc.1"; ADR remains authoritative. Historical rationale untouched.
• Process Engine-era docs - explicitly labelled historical/superseded with pointers to current architecture docs.

Base: c30332bae9c144b28dcc14b356c8b483a0547b1d (integrated main). Intended release identity: v2.0.0-rc.1 (already published tag/release - not modified by this gate).

[RedEyeNinja-BKK]

Docs alignment merged - evidence

Outcome: RC1_DOCUMENTATION_ALIGNED (docs-only gate; no product changes).

• PR docs: align documentation for v2.0.0-rc.1 #3 (docs/rc1-documentation-alignment) merged into main as a normal merge commit.
  • base c30332bae9c144b28dcc14b356c8b483a0547b1d + head 0b55a869ae58fa1cc26192ad973010c35bf74ec6
  • resulting main: 380b8e376e0b1ecac1443ef2c9ee104268236a70
  • exact diff: 13 files - README.md + docs/* only; no product code, tests, CI, pyproject.toml, or package version changes.
• PR CI: run 31248225507 on exact head 0b55a86 - SUCCESS (3.11 93080246592, 3.12 93080246625; 420 tests each; exact checkout identity).
• Final-main push CI: run 31248274719 on 380b8e3 - SUCCESS (3.11 93080365599, 3.12 93080365639; 420 tests each; actual HEAD == expected SHA == 380b8e376e0b1ecac1443ef2c9ee104268236a70).
• Release identity untouched: tag v2.0.0-rc.1 remains at c30332bae9c144b28dcc14b356c8b483a0547b1d (annotated 2eb91f9b…); GitHub pre-release id 367149475 unchanged. Package version remains 2.0.0rc1.
• Documentation changes: README rewritten (RC1 scope, persistence, migrate/export how-to, validation summary, vertical mermaid spine diagram); stale "Phase 2 foundation"/"PR draft: reset Method Factory canonical persistence to SQLite #1 Draft, v2.0.0a1" current-facing text corrected in docs/public-surface.md; ADR-0012 status corrected to released; Process Engine-era docs labelled historical/superseded.

Important: this docs commit moves main ahead of the immutable v2.0.0-rc.1 tag. The released RC1 evidence remains exactly as published; the documentation alignment does not re-tag or modify the release.