Vocab V6 — owned-tree deletion + single-lock-free completion (execution blueprint)

Red-teamed Plan-agent blueprint (2026-06-10) for deleting the now-DEAD owned tree from PersistentVocabARTrie and finishing the single-lock-free transition. Mirrors C2 (byte/char, commit b9570ca). ONE irreversible commit — the build is red until ALL constructors + trait impls are reconciled together (owned fields are woven into every Self {…} builder + trait impl).

Pre-state (committed, 14 commits incl. 406c566): every production ctor flips at construction → route_overlay() always true → every else-arm is dead. Override already removed.

Execution checklist (dependency order — §G)

1. RELOCATE build_disk_char_node_static (disk_io.rs:386) → overlay_serialize.rs as pub(super) — overlay_serialize.rs:190 calls it (R1). DO THIS FIRST.
2. Collapse route-split else-arms to overlay-only (KEEP &mut self — §D, zero trait-signature changes): mutation_api.rs insert→insert_overlay, insert_batch→per-term insert_overlay, insert_with_index→insert_with_index_overlay (delete the owned helpers append_vocab_insert_wal/append_vocab_batch_wal/sync_vocab_wal_after_append/next_unassigned_index_from/validate_index_insert/insert_with_index_no_wal/wal_unavailable_error/map_wal_error); query_api.rs get_index→get_index_lockfree, get_term→reverse_term_map (delete reconstruct_term/reserve_node_map); path_query.rs iter_terms/iter_terms_with_prefix→overlay-only, REWORK get_root_children/get_children_at_path/is_final_at_path over the overlay (char overlay_read.rs template, R8); persistence_api.rs checkpoint→checkpoint_overlay, rework rotate_wal/sync_to_disk_async (drop reverse_index+bloom flush), delete cache_stats.
3. Toggle removal (lockfree_cas.rs): enable_lockfree→pub(crate) (flip_to_overlay still calls it); DELETE insert_cas, is_lockfree_enabled, merge_lockfree_to_persistent. KEEP try_insert_lockfree_path/find_in_lockfree_trie/insert_lockfree_recursive/create_lockfree_path/cas_retries (overlay-live).
4. Struct fields + ctors (dict_impl.rs + mmap_ctor + io_uring_ctor): DELETE fields root/reverse_index/reverse_cache/node_map/next_slot/bloom_filter. KEEP all else incl. dirty/reverse_term_map/lockfree_*/commit_seq/committed_watermark/epoch_manager. Remove those fields + the owned root construction (Box::into_raw/from_raw) + .idx VocabReverseIndex::create from all 4 builders (create mmap/io_uring + open_snapshot/open_with_io_uring); collapse !is_overlay reopen branch (R4). Rewrite Clone (overlay fields None). KEEP explicit unsafe impl Send/Sync (rows 39,40). 4b. DELETE FILE bloom_filter_api.rs + the create_with_bloom/create_with_start_index_and_bloom ctors + mod.rs decl. (Verify no external might_contain/has_bloom_filter caller.)
5. DELETE FILES: disk_io.rs (after relocating §1), reverse_index.rs, reverse_cache.rs, iterators.rs, serialization.rs. types.rs: DELETE VocabTrieNode(320-622)/VocabTrieRoot(625-656)/FLAG_HAS_PARENT_POINTER; KEEP VocabTrieFileHeader/VOCAB_TRIE_MAGIC/VOCAB_HEADER_VERSION_V1+V2/crc32_header/NodeRef-reexport. Drop mod.rs mod-decls + re-exports.
6. mod.rs: DELETE evict_node_at_path(875-976) + rework EvictableARTrie evict-callback to no-op (char template, overlay never evicts finals); update BijectiveDictionary doc (parent-pointer→reverse_term_map); DELETE the 4+helpers unsafe white-box tests (1324-1478) + the test ctor heap_only_vocab_for_unsafe_tests. KEEP public-API tests.
7. DELETE lockfree.rs + concurrent.rs + mod.rs decls (168,169) + re-exports (201,203).
8. External tests (same commit): tests/persistent_artrie_formal_correspondence.rs (drop ConcurrentVocabARTrie/LockFreeVocab/VocabTrieNode imports + 2 Send/Sync asserts + 5 VocabTrieNode white-box tests); DELETE tests/concurrent_checkpoint_publication_correspondence.rs (whole file); tests/persistent_vocab_checkpoint_correspondence.rs (delete 5 ignored + 3 reverse-index tests); tests/persistent_rewrite_compaction_correspondence.rs (delete the 1 ignored sidecar test). NOTE: libgrammstein_support/persistent_artrie_concurrent/lockfree_flip_benchmark insert_cas/enable_lockfree hits are BYTE/CHAR — NO change (verify rg PersistentVocabARTrie).
9. UNSAFE ledgers (LAST): see below.
10. Delete the 11 #[ignore]'d tests + collateral (2 insert_cas tests dict_impl 1525/1547, the 3 reverse-index correspondence tests).

UNSAFE set-equality (the hard gate — scripts/verify-unsafe-boundary-inventory.sh)

• REMOVE 31 inventory rows: 37,38 (concurrent.rs Send/Sync), 41-46 (disk_io.rs), 47,48 (io_uring owned root), 49,50 (lockfree.rs Send/Sync), 51,52 (mmap owned root), 53-56 (mod.rs evict), 57,58 (query_api reconstruct_term), 59-61 (reverse_index.rs mmap), 62-69 (types.rs VocabTrieNode).
• KEEP 2 inventory rows: 39,40 (dict_impl.rs unsafe impl Send/Sync for PersistentVocabARTrie<S>).
• REMOVE 20 contract rows: concurrent-vocab-rwlock-thread-contract; vocab-child-{box-reclaim,box-replacement,raw-map-iteration,read-only-traversal,unique-mutation}; vocab-disk-{box-ownership,child-serialization,node-map-rebuild-contract,root-box-reclaim,root-serialization}; vocab-eviction-{child-drop,target-reference}; vocab-io-uring-root-box-reclaim; vocab-lockfree-thread-contract; vocab-mmap-root-box-reclaim; vocab-public-node-mutation; vocab-query-node-map-traversal; vocab-reverse-index-{map,remap}-lifetime.
• KEEP 1 contract row: persistent-vocab-storage-thread-contract.
• Verify after edits: rg '(unsafe impl|unsafe fn|unsafe\s*\{)' src/persistent_vocab_artrie -g '*.rs' = EXACTLY 2 lines (dict_impl Send+Sync). Any remaining Box::from_raw/&/&mut = a missed deletion.
• Do NOT delete any .tla (PointerOwnership.tla etc. may be shared with byte/char).

Red-team (verify each)

• R1 build_disk_char_node_static relocated (else checkpoint serialize fails) → overlay_serialize round-trip test.
• R2 reestablish_overlay_from_image is owned-free (reads arenas, not self.root) → flip_checkpoint_reopen_roundtrip + flip_crash_recovery.
• R3 get_term reverse coverage: reverse_term_map populated by insert_overlay/insert_with_index_overlay/reestablish/replay incl. "" → empty-string + unicode reverse tests.
• R4 v1 (owned) files unreadable post-deletion — ACCEPTED (owner: legacy rebuilt; NO v1 files in production — all create* write V2). Enumeration fails loudly not silently.
• R5 mmap open_with_recovery: delete owned WAL-replay loop, keep replay_wal_into_overlay_rank_aware → wal-recovery tests.
• R6 entry_count: replay guards get_index_lockfree.is_none() (count only new) → crash-recovery len assert.
• R7 trait honesty (Bijective/Mapped) → bijective_trait_invariant/vocab_trait_honesty/dictionary_law_correspondence.
• R8 get_root_children/Dictionary::root/iter_prefix reworked to overlay (not deleted).
• R9 set-equality gate = THE constraint (kept rows 39,40 untouched).
• R10 --no-default-features + --all-features (io_uring_ctor cfg-gated).
• R11 doctests (lockfree/concurrent doc examples deleted with files); update mod.rs module-doc prose to overlay.
• R12 Clone sets overlay None (empty until rebuilt) — matches char; no production .clone().
• R13 reverse_term_map is Option but always Some post-ctor (enable_lockfree/reestablish); get_term guards gracefully.

Gates (b9570ca parity): cargo build / --no-default-features / --all-features; nextest; cargo test --doc; cargo fmt --check; verify-unsafe-boundary-inventory.sh (set-equality); formal correspondence; loom overlay model; #41 soak; cross-repo liblevenshtein-rust + libgrammstein build.

Full verbatim blueprint (every file:line) is in the session transcript (Plan agent result, 2026-06-10).