Ensure full payloads are not logged unless requested

Problem/Motivation

Scanning by Claude Opus 4.8 identifies some places where the payload still gets logged:

  1. Unvalidated payload embedded in exception messages — contradicts the logging policy (Medium)

  The module goes to real lengths to avoid persisting sensitive payload data: throwInvalidJsonException() and logCorrections() only log
  the full payload when debug_log_full_payload is explicitly enabled, with docblocks noting fields "stored encrypted" must not hit
  logs in plaintext.

  But several exceptions embed the entire raw payload directly in their message:

  - JsonSchemaValidator.php:125 and :133 — "Failed to decode encoded JSON! $encoded_json"
  - JsonSchemaValidator.php:217 and :261 — "Failed to decode encoded JSON! $raw"
  - YamlJsonSchemaValidator.php:39 — interpolates $file_path (low sensitivity, but same pattern)