[loopx-agent]

The SHA-256 ownership checks started failing on main when three result readers defined their own digest patterns. Chat history and Feishu image repair now use the existing generated Python validator for bare digests. The native child-result inbox uses the shared TypeScript validator for the sha256: envelope.

The TypeScript substitution and its consumer-list entry already appear in the broader C1 integration. This PR carries that prerequisite independently so the repository checks can recover while the integration is reviewed. C1 integration #8266

Chat still verifies the digest against the stored image bytes, Feishu still binds the original answer and each image, and the child inbox still binds the original receipt and bytes. The Lark module retains its reviewed size ceiling through a small simplification of the descriptor file read.

Validation

• Reproduced the Python and TypeScript ownership failures on the base.
• Compared the old and canonical validators on 1,754 bare and 1,764 enveloped synthetic values, including wrong length, uppercase, whitespace, non-ASCII input and trailing line breaks.
• 280 focused Python tests, 25 focused TypeScript tests and all 10 diff-selected premerge validators passed.
• Both ownership suites passed with this change applied to the exact current PostgreSQL proposal. PR #8759

The full TypeScript suite passed 6,539 tests with 89 skips. The full Python run stopped after two recovery failures and 6,226 passes. Isolated runs on both the target baseline and this exact head reproduced the missing terminal review during Steward restart and the current_turn_work_changed rejection after restoring the original input for an external Turn retry. The managed quality gate remains held, and the rest of the full Python suite is unverified.

Independent review and hosted CI are pending on the published revision.