docs(spec): resolve FR-010 open questions; pilot Java, classification-pinned tolerance

Records the planning-pass decisions on the FR-010 parent design:
- pilot port = Java (real adopter; recover engine in shared JVM render module)
- cross-port tolerance pinned at classification + canonical value, not byte
  identity (numeric coercion carries documented tolerance)
- intra-port arch = thin codegen + one shared recover() engine; locate split
  into strip/locate/score-select; report is an escalation contract
- field-teaching attrs discrete: @example/@Instruction (string),
  @enumDoc/@enumAlias (existing properties subtype)
- all five open questions answered inline

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dmealing