chore: separate relay prototype history, deployment examples, and operator docs #111

The repository now contains the production session_peer_relay package, the completed experiments/relay69 prototype, reusable deployment examples, the live KR deployment reference, and 105 documentation files in one flat documentation surface. All of these are intentional artifacts, but their current placement makes it easy to run obsolete prototype tests or mistake a generic/static-account unit for the authenticated production topology.

Current evidence on main after #109:

• experiments/relay69: 19 files / about 1,857 lines, plus tests/test_relay69.py; feat: add opt-in paired-device direct and E2EE relay transport #69 is closed and the production implementation lives in session_peer_relay/.
• deploy/session-peer-*.service and deploy/kr/*.service differ materially in identity, auth state, watchdog, readiness, storage and sandbox semantics.
• docs/ contains 105 files / about 12,057 lines but no repository-level docs/README.md that separates user, operator, development and historical material.
• The translation integrity suite is healthy and must remain authoritative.

Proposed scope

1. Inventory every assertion in tests/test_relay69.py; move still-relevant protocol/security coverage to product relay tests before removing it from the default suite.

2. Retain only useful historical prototype evidence under an explicitly historical location such as docs/history/relay69/, or rely on Git history where the files add no current value.

3. Reorganize deployment material so reusable examples and Abruption's deployed KR reference cannot be confused, for example:

   deploy/
     examples/
       static-account/
       authenticated-control/
     ops/
       abruption-kr/
   

4. Add docs/README.md as the repository documentation entry point, categorizing user guides, operator runbooks, development/architecture, and historical validation records.

5. Update all links, packaging allowlists and docs/i18n-manifest.json; keep all translated documentation structurally aligned.

Acceptance criteria

• No unique replay, E2EE, pinning, lifecycle or relay framing regression coverage is lost.
• The default test suite no longer imports the completed prototype implementation.
• Generic units state their supported authentication mode and lifecycle assumptions in their path and README.
• KR files remain exact, secret-free operational references and are clearly marked as instance-specific rather than reusable defaults.
• docs/README.md provides a short audience-based navigation surface in English, Korean, Japanese and Simplified Chinese.
• Wheel/sdist contents remain intentional; prototype sources remain excluded.
• Full Python, control integration, packaging and documentation-i18n CI passes.

Non-goals

• Splitting the relay or control plane into a separate repository.
• Refactoring the 3,972-line standalone session_peer.py; that needs a separate design because zero-install SSH deployment depends on a single-file artifact.
• Changing live KR services, credentials, state, Caddy, OAuth or backup policy as part of repository moves.