Plan Approval: fingerprint blocks on a complete Testing Contract (D)

[SaRedfiche]

Part of #1374.

Problem

The fingerprint binds the code-generation plan, which embeds a ## Testing Contract JSON block produced by aidlc-testing-posture.ts render. If render is still running or wrote a partial contract (a backgrounded testing-posture render & fed a PARTIAL Testing Contract on the stalled customer run), parseTestingContract returns null, contractValid is false, and the approval is refused later with:

Plan Approval fingerprint does not match the active intent, target, stage attempt, plan, instructions, and Testing Contract. Re-run the fingerprint command, re-present the plan, and approve again.

The fingerprint command will happily fingerprint a plan whose Testing Contract is incomplete, so the failure surfaces only at the gate.

Verbatim error string(s) addressed

• Plan Approval fingerprint does not match the active intent, target, stage attempt, plan, instructions, and Testing Contract. Re-run the fingerprint command, re-present the plan, and approve again.
• Plan Approval requires the current Testing Contract (planApprovalQuestionEvidence, core/tools/aidlc-testing-posture.ts)

Proposed behavior

Before fingerprinting, require a COMPLETE Testing Contract. If testing-posture render is still running or the embedded contract is incomplete/partial, refuse with a distinct message:

Testing Contract still rendering — wait for render to complete (or re-run it synchronously) before fingerprinting.

Options: make render synchronous by contract, or gate the fingerprint on a render completion marker so a partial ## Testing Contract can never be fingerprinted.

Acceptance criteria

• fingerprint refuses with the "Testing Contract still rendering / incomplete" message when the embedded contract is partial or absent, instead of fingerprinting it.
• A complete, current Testing Contract fingerprints exactly as today.
• The guard invariant is unchanged; this only moves the incomplete-contract detection from the gate to fingerprint time.