Mega Beta5

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Summary

Beta 5 hardening rollup. This PR is rebased on current master and now contains the complete fixes for:

• Same-size unsized updates staying in place without corrupting archived strings.
• LockMap can retain an empty lock entry after a cancelled acquirer #33: cancelled LockMap acquirers no longer retain empty lock entries.
• Vacuum on persisted tables does not reclaim on-disk space #31: vacuum-freed data pages are persisted as reusable ranges across reloads, with ordered reclamation barriers. Online vacuum does not claim file truncation.

Regression coverage

• same_length_update_stays_in_place
• cancelled_acquirer_removes_the_abandoned_entry
• cleanup_waits_for_every_acquirer_to_drop
• vacuum_reclamation_waits_for_preceding_row_moves
• test_vacuum_on_persisted_table_survives_reload

The persisted-vacuum test proves reuse survives two reloads, a reused insert does not grow .wt.data, and consumed free ranges cannot overwrite a previously reused row.

Validation

• cargo fmt --check
• cargo clippy --all-targets -- -D warnings
• cargo test: 151 library tests, 356 integration tests with 2 intentional ignores, and 2 doctests

Fixes #31.
Fixes #33.

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Logical WTI persistence review follow-up is included in this branch at 788c8ee.

1. Ordering: BatchOperation already sorts every per-index stream by event ID before engine dispatch. SpaceLogicalIndex now sorts again at the logical-to-structural boundary. A reversed Insert/Remove delivery regression test proves event-ID order is restored before shadow mutation.

2. Divergence: removed the generic bail path. Remove divergence is checked before mutating the shadow and returns public PersistenceIndexCorruption with the index path and reason. PersistenceLifecycle classifies it as PersistenceError::IndexCorruption, enters terminal Failed state, and rejects all later persistence submissions with the same error. The quarantine boundary is intentionally the entire table persistence engine: continuing row or sibling-index writes would knowingly create an inconsistent store.

3. Codegen feature: the proc-macro feature check is intentional because WorkTable forwards logical-index-persistence to worktable_codegen. Emitting downstream cfg attributes would inspect the consuming package's unrelated feature namespace. Feature-off and feature-on expansion tests now verify IndexMap versus PersistentWtiIndex selection.

4/5. The fixed 64 inline mutex-stripe footprint is documented, reads never touch it, and DefaultHasher striping is explicitly documented as per-key exclusion only with no key/range-order meaning.

The synthetic index=0 and max_value=value fields are documented as a logical marker rather than structural metadata. The shadow validates the marker and derives the actual node position and maximum through native WTI CDC; replacement coverage verifies same-key link changes.

Final local gate on the exact PR head: all-feature Clippy clean; 159 library tests passed; 359 integration tests passed; 3 pre-existing tests ignored.

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Addressed all 5 self-review findings in d48e1ab (stacked on this branch):

• F1 (generator inconsistency): full-row update() now uses the in-place same-size path when the table has no secondary indexes. On investigation, gen_non_unique_update (updates a non-unique-indexed column) and indexed full-row updates correctly stay on reinsert — the fast path only applies when no updated field is indexed, and the custom single-column updates (gen_unique_update/gen_pk_update) already get it via gen_size_check. Documented so the scoping isn't mistaken for an oversight.
• F2: update_in_place now documents it emits no persistence CDC and must not be used on persisted tables; the persisted generator keeps the reinsert path.
• F3: commented that correctness relies on update_in_place's slot-length re-check + reinsert fallback, not on the pre-lock size decision being current.
• F4: dropped the redundant row.clone() inside update_in_place.
• F5: added concurrent_reads_during_in_place_update_never_tear — 3 readers vs a writer doing 20k same-size in-place updates, asserting no torn reads. Passes, empirically confirming PublishedRow::replace swaps versions atomically.

Full integration suite: 359 passed / 0 failed.