READY-TO-ASSEMBLE-LEGO1-PATCH1 09 — [P1-6] Canonical Serialization & Artifact Binding — 2026-06-22

Closes Codex P1-6. Gate: REGISTRATION_HOLD · CAN_PROCEED = NO · 0 runtime mutations. Design-only.

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1. Defect (reconstructed)

Prior hash input operation_code|protocol_version|act_type|governing_authority_ref had no escaping, normalization, encoding, null handling, field-version, or canonical serialization — delimiter ambiguity ⇒ non-portable evidence. SUPERSEDED.

2. cser-v1 — versioned canonical serialization

Rule	Specification
Format	Canonical JSON (JCS / RFC 8785 style), not delimiter-joined strings
Field names	fixed, explicit; no positional fields
Key order	lexicographic by Unicode code point
Strings	UTF-8, Unicode NFC normalized
Whitespace	none (no insignificant whitespace)
Numbers	shortest round-trip form per RFC 8785
Null handling	explicit null (a missing field ≠ null; both represented distinctly)
Encoding	UTF-8 bytes
Version tag	every serialized object includes "cser":"v1" as the first canonical field-value pair conceptually (covered by digest domain)
Digest	SHA-256 over the canonical UTF-8 byte string

3. Bound artifacts (each gets a cser-v1 digest)

Artifact	Object serialized	Digest name
Plan	{cser, plan_id, plan_revision, carrier:"C1"}	plan_digest
Schema	the file-03 field set + constraints (canonical)	schema_digest
Value manifest	the file-04 R_C1 projection (sorted by operation_code)	manifest_digest
Per-value record	{cser, operation_code, protocol_version, act_type, semantics_frozen, governing_authority_ref}	value_digest[i]
Authorization	the verifier-bound scope (file 05 §2) incl. plan/schema/manifest digests	bound inside grant scope
Execution log	per-state dispatch result (idempotency_root, mode, correlation_id)	exec_log_digest
Readback	post-build snapshot (file-10 base plan)	readback_digest

4. Binding chain

plan_digest ⊃ schema_digest + manifest_digest; the authorization grant (file 05) binds plan_revision + manifest_digest + schema_digest; the execution records idempotency_root + per-state results; the readback recomputes value_digest[i] and manifest_digest and asserts equality (test T16, file 08). A mismatch anywhere ⇒ fail-closed (no PASS/seal). Evidence is portable because every digest is over cser-v1 bytes, not ambiguous delimiters.

5. Boundary attestation

Design-only serialization spec; nothing hashed in runtime, nothing written. REGISTRATION_HOLD retained; CAN_PROCEED = NO; 0 runtime mutations. Supersedes prior file-10 §3 hashing rule.