Reopen an existing database: first query and first vector query, native against JVM #355

Problem

I want to know what opening an existing database plus the first query and the first vector query (lazy graph build) cost on each wheel, what warm-up advice follows, and what heap floor a reopen needs.

It is one row of the bindings study list. It was held on stale pins and re-pins after the 26.11.1 release wheels exist.

Priority: P3 (tier 1 of the re-pin order).

Acceptance

• The study is re-pinned to the 26.11.1 pair and dry-run
• It runs and is scored
• Warm-up advice and a heap floor go into the docs

Results and the scorer output go in this issue as comments. Numbers are generated by script from the result files, never typed.