Move the ready/wrap branch and synchronization ordering from ZSTDMT_tryGetInputRange into Rust. The Rust policy now waits for the prefix range, invokes the C-owned prefix move, waits for the selected source range, and publishes the buffer; C retains memmove, private buffer fields, round-buffer state, and LDM callbacks behind the projection. Add ABI assertions and focused wrapped/ordinary ordering tests.
Test Plan: git diff --cached --check; focused Rust tests added; full capped Rust/native/original-suite verification follows.
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