Make the BIMRI README mechanism-led and document safe local use

[EvolutionUnleashed]

What changed

• Replaces the 905-line README with a 403-line buyer-facing page built around BIMRI's mechanisms: owner authority, stable-key conflict handling, a model-free memory engine, a bounded hot view, crash recovery, and folder portability.
• Adds five concrete use cases, a text diagram, a production concurrency receipt, measured performance, plain boundaries, and a shorter FAQ.
• Moves the operational specification into a new 619-line REFERENCE.md, with links for commands, tiers, retrieval, review, recovery, storage, performance, and portability.
• Adds an explicit Claude Cowork section: local desktop execution only; cloud sessions are unsupported because the required shared lock and atomic-rename boundary is unverified. It also documents the one-runtime-at-a-time rule and the required AGENTS.md folder instruction.
• Adds a collapsed, paste-ready upgrade prompt directly beneath installation. It detects supported versions from v1 through v5.1.1, requires a verified whole-project backup and quiescence, preserves memory and instructions, fails closed, rebinds Python, tests hooks, and verifies with doctor --read-only plus status.
• Tightens public claims against the engine, protocol, repository history, and official Claude Code, Cowork, and Codex memory documentation.

Validation

• git diff --check: clean
• Internal Markdown paths and anchors: clean
• Code fences and <details> pairing: clean
• Focused installer/upgrade safety tests: 5 passed
  • preserves project files and portable engine root
  • deterministic v1/v2 migration
  • v5.0 profile update
  • current-store quiescence requirement
  • code update preserves governance
• Test inventory: 255 test methods
• Full GitHub Actions matrix runs Python 3.8 and 3.12 on Linux and Windows, including the gated benchmark

Official runtime references: Claude Cowork architecture, Claude Code memory, Codex local memories.