EXP-0152: identify governed result content

[buger]

Stacked on EXP-0151 / PR #590.

Adds one opt-in governed result identity at the Probe host boundary that owns both the matched v2 invocation receipt and schema-valid parsed JSON.

Scope:

• content-only, domain-separated SHA-256 over one normalized JSON serialization
• canonical byte count and exact public identified-result overload
• one-read schema and selector snapshots before await
• deeply frozen normalized data, v2 receipt, identity, and top-level result
• legacy v1/v2 lanes and regular answer remain unchanged

Evidence:

• focused node suite: 48/48 pass, zero fail/cancel/skip/todo
• all 15 EXP-0152 oracle groups, including awaited repository TypeScript compiler fixture
• T10 captures the exact actual validation.parsed graph and proves root, array, and nested-object separation
• exact four paths; changed nonblank 84 product / 141 test (two-sided)
• frozen codex.js, schemaUtils.js, governed profile, and regular answer hashes pass
• no model or application network call

Nonclaims: no Visor linkage, persistence, Proof admission/freshness, replay protection, JCS/RFC 8785, or production readiness.