Osteosarc 0.2.1

Adds bounded indexed mate/SA recovery while preserving seed/context records, original record fields and duplicate multiplicity. Partners are matched within the same source, read group and segment. Receipts report visited windows, unresolved or conflicting pointers, missing sequence, repeated links and acquisition limits without claiming complete template closure.

The review fixes retain previously fetched candidates for later links into visited windows, validate seed interval/base budgets before read extraction, and stop streaming acquisition on record overflow. Candidate lookup is indexed by placement, and recovered output is checked against its original binary record multiset. Verified intermediates support retries; source/header/index/reference changes fail explicitly.

Rebased onto released #22. Addresses #13; scientific assembly-context parity is covered by the downstream consumer migrations.

Validation: 207 tests, ruff, strict documentation build, source/wheel build and the full offline suite against the built wheel outside the checkout. Regression tests cover recursive links, duplicates, acquisition budgets, unselected candidate limits, subprocess failure/timeout cleanup and interrupted retries.