Rewrite README as reviewer-oriented deterministic replay-validation front page

[ProfRandom92]

Motivation

• Provide a concise, reviewer-focused front page that explains the deterministic operational replay-validation goals and scope while preserving the existing centered logo/header and badges.
• Make the project immediately scannable for reviewers with GitHub-native Mermaid diagrams that map architecture, artifact pipelines, fixture coverage, failure taxonomy, CI merge gates, and roadmap.
• Ensure README references only existing, committed artifacts and registered failure labels, and satisfy the repository's deterministic artifact-drift checks.

Description

• Rewrote README.md body while preserving the original top logo/header block and badges, and added the required tagline and core principle text near the top.
• Added six GitHub-native Mermaid diagrams: replay validation model, artifact evidence pipeline, fixture family coverage, failure taxonomy map, CI/merge gate flow, and roadmap flow.
• Added a minimal deterministic JSON example using only registered failure labels, a proof-artifacts table referencing existing artifact files, the three fixture families, and local verification commands.
• Inserted drift-locked benchmark metrics (derived from committed artifacts) so repository artifact-drift checks align with published values; no other files were modified.

Testing

• Ran npm run check (runs layout, typecheck, validate, build, and pytest); result: success and full test suite passed (222 tests passed).
• Ran targeted verification commands used by reviewers: pytest tests/test_failure_taxonomy.py -q, pytest tests/test_multi_family_admissibility_artifact.py -q, and pytest tests/test_multi_family_svg_renderer.py -q; all passed as part of the npm run check run.

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Codex Task

[gemini-code-assist]

Code Review

This pull request extensively refactors the README.md to provide a more structured and comprehensive overview of the CompTextv7 project, introducing new sections for project definitions, validation models, artifact pipelines, and a detailed failure taxonomy. The changes also include updated benchmark metrics, local verification instructions, and several Mermaid diagrams illustrating the system architecture and CI processes. Review feedback identifies opportunities to improve the repository map by including the core engine directory and to align the project roadmap with the broader milestones defined in the style guide.