docs(#208): implementation plan — @sql/@Unmanaged DDL-ownership escape valves

Task-by-task plan for FR #208 (spec 2026-07-17-issue-208-…-design.md). Four phases:
1. Coordinated 5-port registration of @SQL + @Unmanaged on source.rdb (atomic —
   registry-conformance byte-match reds any laggard).
2. TS reference: MetaSource accessors → loader validation (6 fail-closed rules) →
   the suppression rule (classify DDL-ownership before viewIsDerived) → @SQL
   migrate branch (verbatim body + fingerprint + adopt-view ceremony) → @Unmanaged
   branch (skip create/drop/drift + introspection-side silencing). Checkpoint.
3. 4-port validation fan-out (Java/Python/C# accessors + rules; Kotlin rides Java)
   + shared conformance error-fixtures (landed only once all ports validate) +
   cross-port divergence review.
4. ADR-0043 + migration/verify docs rewrites.

TDD steps throughout; TS-only migrate/verify lowering (ADR-0015); the registration-
coupling traps are called out explicitly.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NGQ7oSuNcjhsMHWwZzhBwr

Author: dmealing