Establish public corporate developer governance and review portal

[blackmore-technology-group]

Summary

Builds the next public engineering layer around ENTITY so Blackmore Technology Group Limited exposes a coherent developer/governance surface rather than only repository-level documentation.

Added

• DEVELOPERS.md — single public engineering gateway by contributor objective
• evidence-gated release policy
• contributor-recognition policy
• public interoperability status/scoreboard
• independent security-review program
• technical-paper index and first technical note on the three verification boundaries
• formal ADR process

Improved

• expands project/protocol governance with decision classes, release governance, conformance governance, maintainer boundaries and historical-integrity rules
• turns the architecture directory README into an ADR/architecture index
• updates SECURITY.md from stale v3.0.1 support language to the current protected v3.3.0 release
• makes the independent-review boundary explicit throughout

Claim boundaries preserved

• BTG-controlled language implementations remain controlled reproducibility evidence, not unrelated third-party validation.
• Independent implementation/interoperability remains pending.
• Independent external security review remains pending.
• Protocol 1.0 remains a separate frozen historical conformance target.
• No verifier, sealed kit or historical signed evidence is weakened or rewritten.

Why

The repository already has strong engineering evidence and contribution surfaces. This PR adds the governance, security-review, release-discipline, contributor-recognition and interoperability-status layers expected of a mature public engineering program.