[7.4] Documentation

[romejoe]

Summary

Comprehensive documentation for users, security-conscious evaluators, and contributors.

Requirements

• User guide (README.md):
  • Installation and first-time setup
  • Creating profiles and adding secrets
  • Using inline references (syntax guide with examples)
  • Copy, reveal, and inline edit workflows
  • Binary attachments
  • Master password and keyring setup
  • Mobile usage notes
  • FAQ
• Security model document (SECURITY.md):
  • Threat model (what it protects against, what it doesn't)
  • Encryption details (KDBX format, KDF parameters, cipher options)
  • Memory handling and known limitations
  • Clipboard behavior
  • Recommendations (KDF tuning, .gitignore, sync strategy)
• Contributing guide (CONTRIBUTING.md):
  • Dev setup and build instructions
  • Architecture overview
  • Testing instructions
  • Code style and PR guidelines

Acceptance Criteria

• A new user can set up the plugin using only the README
• Security-conscious users can evaluate the threat model from SECURITY.md
• A developer can set up a dev environment and submit a PR using CONTRIBUTING.md

Dependencies

• All prior phases (docs describe final functionality)