test(periodic-report): preserve Turn milestones through retry recovery

[hhyykk]

Draft: durable caller coverage for the existing Turn replan and optional post-writeback recovery contract. A primary Turn commit must retain its accepted successor intent from the original source even after later Todo/Vision writes; replay must not invoke the host, repeat primary writeback or spend again. Optional capability OFF must create no sidecar and perform no optional source read.

One shared fixture now covers 12 cases: File/SQLite generic CLI and File dsh, each with ordinary execution, failure before optional dispatch, response loss after sidecar commit, and optional capability disabled. The managed cases use the real --dsh-runner adapter with a deterministic local runner; they do not call a live model. No production files are stacked into this branch.

The shared CLI hook drain and canonical source recovery are already merged in #5939. This draft still depends on native successor source binding #5935 at 1a34dcc36eebe2f6aa23b06398996e8affb24724 and managed candidate transport #5954 at eac312f26acfc0bcc79faf6aa4db463e76d1aa60.

Validation:

• All 12 caller cases passed in a frozen composition based on main 05af21dd4cbc8256af1da9746a34abc13085cfd3 with those two runtime repairs, retaining main's strengthened terminal-Vision guard.
• Fresh composed wheel and sdist each passed 52 selected cases, including the 12 caller cases. Eighteen production-file hashes match the composition; imports use isolated site-packages without source fallback. The normal Chat bundle was rebuilt before packaging.
• The same File standard cases still fail against unmodified production code at that main revision: generic CLI commits but emits no native successor intent; dsh rejects the replan before writeback because the adapter loses its material Vision. These are genuine remaining dependency failures, not the older missing-hook observation.
• Risk premerge passed on this test-only branch. The only edit after composed qualification removed an obsolete comment; parsed test logic is identical.

Keep this PR draft until the runtime dependencies are adopted and the resulting main is rerun. Live SDK/model, full PostgreSQL Turn, frontend and Lark journeys remain unqualified. The future-facing pass reuses the existing fixture and shared candidate data rather than adding a separate managed-host expectation model.