DETERMINISTIC BLACKJACK — V9.2.117-UAT PREAMBLE FIREWALL PATCH

1. LINK no longer requires a known preamble closing bankroll.
2. Linked preamble contributes chronology/context only. Formal session money always starts on a fresh £100 research frame from the separately confirmed Hand-1 platform balance.
3. A known preamble closing platform balance may produce an informational continuity note, but cannot block linkage.
4. Choosing INDEPENDENT keeps the accepted preamble file as historical evidence; after the independent formal session is successfully saved it is retired from the pending queue and marked NOT_LINKED_FORMAL_SESSION so it cannot drift into Session 17.
5. New screenshot-request generation removes stale preamble_screenshot_chatgpt_request_*.txt request artefacts only. Candidate files and accepted/linked evidence are never deleted by this cleanup.
6. Existing accepted PREAMBLE-20260926-023139 remains unchanged and unconsumed. Existing canonical PNG archive is untouched.

UAT EXPECTATION
- Start CLI and select L.
- Answer N to Record/use a PREAMBLE (the accepted preamble is already pending).
- At UNCONSUMED PREAMBLE choose L.
- Link must proceed even though CLOSING_BANKROLL_STATUS is UNKNOWN.
- Formal Hand-1 balance is entered independently and defines a fresh £100 research frame.