diff --git a/docs/TEST_COVERAGE.md b/docs/TEST_COVERAGE.md
index 13c6b3401..4f5f7d7bf 100644
--- a/docs/TEST_COVERAGE.md
+++ b/docs/TEST_COVERAGE.md
@@ -6,7 +6,7 @@
 
 **Result**: 1,337 passing tests and 9 ignored tests (1,346 total)
 
-This covers the unreleased file-format-v8 work (#287, #371): the index-key value-collision fix, the v7→v8 migration, and the drop of formats v1–v6. It otherwise still covers the public database API, the Datalog engine, storage and recovery paths, v2.0.0's locking and structured-error-code changes, and v2.0.1's regression test for rebuilding indexes on open after several checkpoints (#370). Merged from the v2.x line: `tests/point_query_history_test.rs` and new storage unit tests check that attribute-narrowed bound-entity lookups return exactly what a full scan returns, and that `net_asserted_facts` matches its previous implementation on randomized histories (#323). Attribute-scan tests check that the AEVT range covers exactly the queried attribute, including non-ASCII names such as `:丿` and prefix siblings such as `:ab` for `:a` (#381). Incremental B+tree rebuild tests check that checkpoints which copy untouched index leaves produce exactly the entries and file checksum a full rebuild would, including over repeated checkpoints, that single-fact checkpoints do not fragment the index, and that a damaged slot directory is rejected rather than copied (#315). B+tree cursor tests check that every scan walks the tree, not the leaf `next_leaf` chain: full scans and start positions match the input, `seek` from the current position lands where a fresh descent from the root would (randomized, plus within a leaf, to a sibling, across subtrees, past the end, into the gap after a leaf, and backwards as a no-op), a seek to the sibling leaf reads exactly one page, reads are unchanged with every `next_leaf` zeroed, a child pointer into a non-B+tree page is STG-013, and a cycle in child pointers is an error, not a hang (v8 storage format PR 1, #374). Directory-sync unit tests check that creating the `.graph` file or the WAL, and deleting the WAL, fsync the parent directory after the file operation, and that reopening an existing file does not (#389). Disjunction tests check that `or-join` returns an empty result, not INT-031, when no rows reach it: on an empty database, after a pattern that matches nothing, after a `not` that removes every row, and in a rule body (#405). A stratification unit test builds the same two-rule negative cycle 64 times and checks that the INT-054 message names the same predicate pair every time (#410). Magic-sets tests check that a recursive rule with a literal start that recurses through another rule returns the same results as without the literal (#297). API tests check that `execute()` and `WriteTransaction::execute()` reject `$slot` bind tokens in every position with API-010 (#407). The REPL `run()` test now runs in a child process with null stdin, so it no longer hangs when the test runner's stdin is an open non-TTY stream (#415). v8 page-format tests (PR 2, #374, #388) check the 24-byte page header (a flipped bit, a wrong page id and a future generation each give their own STG code, legacy page types fail before the CRC, and a failed page is never cached), meta-page encoding, the free-list chain, WAL v2's base generation, and every row of the meta-selection table: both slots valid, a torn newest slot with the WAL's base generation (opens at the older one), a WAL newer than the valid meta, pages of the next generation on the free list or past `page_count` with no WAL (all STG-033, with the file unmodified), an unknown feature bit (STG-034), and a pre-release v8 single header (STG-032). Fault-injection tests crash `save()` at every page write (cleanly and with torn pages, including the meta write) and every sync, and crash a v7 migration at every write; each reopen finds exactly the old or the new checkpoint, and every reachable page plus the free list covers the file exactly. Twenty-five consecutive saves never write a page the previous meta references. Covering-key tests (PR 3, #433) check that byte order equals logical order for every key component and value type on random tuples (negative, zero and large integers, NaN and ±0.0, strings with 0x00, 64- and 65-byte strings, FOREVER, newest-transaction-first) and that every component round-trips; that prefix-compressed leaves and shortest-separator internal nodes round-trip, agree with a linear scan, keep `max(left) < s ≤ min(right)`, and reject an overflow; that the byte-key B+tree's builds, incremental rebuilds, cursor and `seek` match their expected sets; that dictionary ids are assigned once, never reused, shared between a keyword attribute and value, and deterministic; that a re-asserted or retracted long value writes no new value page and a forced hash collision still finds the right value; that one transaction with two timestamps is STG-037 and a missing dictionary entry STG-036; that committed reads by entity, entity and attribute, attribute, and in full equal an in-memory model across eight checkpoints and a reopen; that short-valued reads touch no value page; that a v7 file with every value type, long strings, refs and retractions migrates to exactly the same facts; that a pre-covering-key v8 file is STG-032; and that string values over 4,068 bytes and attributes or keywords over 1,024 bytes are WAL-003. A WAL test checks that reopening next to a fully checkpointed WAL does not reuse transaction numbers (#447). Copy-on-write checkpoint tests (PR 4, #434) check that lazy free-list pops and pushes conserve every page across page boundaries, partial head pages and chain exhaustion, never hand out a page freed in the same generation, and share unread chain pages unchanged; that a copy-on-write insert equals a sorted merge for random batches (including keys below the first and above the last, many into one leaf, root growth to depth 3, and 1 KB separators that split internal nodes), leaves the old tree readable and unchanged, frees exactly the replaced nodes, writes only new pages, writes exactly one leaf and two internal nodes for one entry in a depth-3 tree, and does not fragment leaves under single inserts; that a checkpoint after 1 or 100 right-edge facts writes at most the tree-depth difference more pages at 100,000 facts than at 10,000, and at most one path per new entry per tree for random keys; and that four reader threads querying throughout 40 checkpoints never fail and never see the fact count go backwards. Hardening tests (PR 5) damage an index leaf, an internal node, a dictionary leaf, a value page and a free-list page in turn. Every committed read or checkpoint that reaches the damaged page fails with STG-029, never with wrong or fewer rows. A query through `Minigraf` on a file with damaged leaves fails with STG-029, and the file still opens at its last checkpoint. A size test measures at most 200 bytes per fact (142 measured) on 144k facts in #433's shape; its 1.15M-fact variant is ignored locally and runs in the nightly smoke workflow. A shared dictionary-cache test checks that cached ident and timestamp lookups return the same facts and that the cache stays bounded. Merged from the v2.x line: storage and `edge_cases_test.rs` tests check that more than 65,535 uncheckpointed facts each resolve to their own fact through entity lookups and attribute scans, in memory and file-backed (#445). Merged from the v2.x line: `tests/golden_corpus_test.rs` opens a copy of each committed golden file in `tests/golden/` (v7 files written by minigraf 2.0.3: one checkpoint, several checkpoints, indexes rebuilt on open, a crash-left WAL, an already-checkpointed WAL, same-transaction multi-values) and checks its manifest's CRC32, `tx_count` and query results after open, after a checkpoint and reopen, and after one more write; a second test checks that every golden file has a manifest (#391). On `v3` the same test checks that each v7 file has a v8 meta page after its first open and gives the same results after reopening the migrated file, and adds seven v8 golden files (one checkpoint, seven copy-on-write checkpoints, a crash-left v2 WAL, an already-checkpointed v2 WAL, same-transaction multi-values, a v7 file migrated in place, and long values at the size limits); the #371 queries, skipped on v2.x, run and pass. Integrity tests (#373) check that intact files verify with no problems and an exact fact and page count, and that `verify` reports each kind of damage with its code: an EAVT, AEVT, AVET or VAET leaf missing an entry (STG-038), keys out of order and a page reached from two trees (STG-039), a rotted index leaf (STG-029), a free page still in use and a leaked page (STG-035), a missing transaction entry (STG-036), and an entity id whose UUID maps to another id (STG-040). After each index or free-list damage, `rebuild_indexes` leaves a file that verifies clean, reads back every fact and accounts for every page. The source is an index that agrees with another one, or the only intact one; three intact indexes that all disagree, or a damaged dictionary, give STG-041 with the file unchanged. A rebuild commits pending facts, including new ids and long values. A crash at every write (clean and torn) and every sync of a rebuild reopens either at the old generation with only its old damage or at the new one with none, never losing a fact. Through `Minigraf` (`tests/integrity_test.rs`), a rebuild commits WAL entries and deletes the WAL, and flipping a byte in each leaf of a file in turn is always reported, then either repaired (index leaves) or refused with STG-041 and the file unchanged (dictionary leaves). Live-read tests (#379) check that `triple_len` ends exactly where `tx↓` begins for every value type and index; that on random histories (several valid-time windows, retractions, re-assertions, several values per attribute, long values, 12 transactions per checkpoint) the committed live read for every scan kind and `:as-of` point is exactly the net-asserted set, that it stays equivalent with pending facts on top, and after reopen; and that a point read on a triple asserted and retracted 2,000 times reads under a third of the pages a history read does, with or without `:as-of`. `tests/live_reads_test.rs` runs the same history in a checkpointed file database and in memory and checks that point, attribute, full-scan, join, valid-time, `:as-of` and rule queries return the same rows, before and after reopen. One-window tests (#435) check that `net_asserted_facts` keeps each triple's newest transaction only (a later window replaces an earlier one, closing an open window, a retraction in the newest transaction hides it, records with two windows in one transaction keep both, once each) against a per-triple model on random histories; that the on-disk key walk agrees at every `:as-of` before and after reopen; and that `API-011` rejects two windows of one fact in one transaction without taking a `tx_count`. `tests/valid_time_window_test.rs` checks replacing, closing, extending, reopening and retract-then-reassert through entity-bound and attribute queries in memory, on a checkpointed file and after reopen, and `API-011` from `transact` and from `WriteTransaction::commit`. Cursor tests (#432, `tests/cursor_test.rs`) check that `query()` batches partition the `execute()` answer for several batch sizes (never empty, never over `max_rows`, `max_rows == 0` still progresses, `None` stays `None`), that the iterator and aggregates, rules, `:as-of` and `:any-valid-time` match `execute()`, that a cursor opened before a `transact`, a `WriteTransaction` commit, a retract or a checkpoint returns the pre-write answer to the end (in memory and file-backed), that `transact`/`retract`/`rule` are `API-012` and bind slots `API-010`, that a `WriteTransaction` thread gets `INT-001`, that rule limits give `INT-020` as from `execute()`, that `PreparedQuery::query` matches `PreparedQuery::execute`, and that a cursor is `Send` and outlives its database handle. Fact-log tests (#430, `tests/fact_log_test.rs`) check that `fact_log()` returns exactly the records written (assertions and retractions, with `tx_count` and `tx_id`) in memory, with everything pending, half checkpointed, fully checkpointed and after reopen, in both orders, with windows of 1 to 1,000 records and batch sizes of 1 to 1,000, in non-decreasing `tx_count` in Tx order; that every layout gives identical records, including valid-time windows and long string values; that a transaction larger than the window is split with no loss or duplicate; that attribute, attribute-prefix, entity and tx-range filters and their combinations match a model, and unknown names match nothing; that writes after open are not in the log; that `checkpoint()` and `rebuild_indexes()` are `API-013` while a log is open (a checkpoint with nothing to write is allowed), that automatic checkpoints from `execute()` and `WriteTransaction::commit` wait for the log, and that closing, dropping or finishing the log releases the database; that a `WriteTransaction` thread gets `INT-001`; and that a log is `Send`, outlives its database handle, and the deferred writes replay on the next open. Read-only open tests (#429, `tests/read_only_open_test.rs`) check that a read-only handle on a file with checkpointed facts and a pending WAL returns the same query results, `tx_count` and fact log as a read-write open; that queries, a cursor, a fact log, `verify`, `prepare`, rules and a UDF leave the `.graph` and WAL bytes and the `.graph` mtime unchanged, and no WAL is created; that `transact`, `retract`, `begin_write`, `checkpoint` and `rebuild_indexes` are `API-014` without taking a `tx_count`, also on a read-only in-memory database and through the builder path; that a missing file is `STG-042` and nothing is created; that an empty file is an empty database and stays 0 bytes; that read-only handles share a file while a read-write one is refused with `STG-025`, both ways; that a file without write permission opens read-only; and that small and whole-file page caches work. File-backend unit tests check that a shared-mode backend refuses page writes and syncs with `INT-056`, that the in-process registry counts readers and admits readers or one writer (also without kernel locks), and that a reader in another process shares the file with a reader here and refuses a writer here with `STG-026`. Storage unit tests check that a read-only open of a v7 file at every point of an interrupted migration (clean and torn writes) sees every fact and writes nothing, and that an empty backend stays empty. `tests/golden_corpus_test.rs` opens a copy of every golden file read-only first and checks its `tx_count` and queries, and that neither the file nor its WAL changes. Log-writer tests (#431, `tests/log_writer_test.rs`) copy a source's fact log (assertions, retractions, an explicit valid-time window, long strings, refs, keywords, checkpointed and pending facts) through `LogWriter` and check that the new file has no `.partial` or WAL, verifies clean, and gives the source's `tx_count`, fact log and query results (current, `:valid-at`, `:any-valid-time`, every `:as-of`, and entity-, attribute- and value-bound lookups) read-write, read-only and after reopen (#370); that it takes new writes at the source's next `tx_count`; that 90,000 facts over two batch commits verify clean and count correctly at `:as-of`; that a purged middle transaction is a hole whose `:as-of` equals the one before, and trailing holes keep the counter through `advance_tx_count`; that an empty log is an empty database with the counter; that `tx_count` 0, a lower or closed transaction and a backwards advance are `API-015`, a second `tx_id` `API-016`, a second window `API-011` and oversize values or idents `WAL-003`, each leaving the writer usable and the output exact, with repeats written once; that an existing target or WAL is `STG-043`, a second writer `STG-025` and `read_only` `API-014`; that a stale `.partial` is reused; that dropping an unfinished writer leaves nothing; that `finish` refuses a target created during the build and leaves it untouched; and that `LogWriter` is `Send`. Unit tests check that a batch commits only when a transaction opens past the batch size, never splitting one, and that `FileBackend::truncate` empties a file. A unit test in `error.rs` checks that `MinigrafError::invalid_argument` and `MinigrafError::closed`, the constructors for language bindings, give API-017 and API-018 with their text. Three `BrowserDb` tests (wasm32, run with `wasm-bindgen-test` in a browser, not counted above) check that `query()` batches of 1, 7 and 1,000 give the rows of `execute()`, that a cursor keeps the answer from when it opened and returns the end after `close()`, and that a `transact` is API-012. The wasm32 targets run in CI (`.github/workflows/wasm.yml`). In a browser (`wasm-pack test --headless`, Firefox and Chrome): 23 `wasm_bindgen_test` tests: twelve for `BrowserDb` (including IndexedDB persistence and the cursor), nine for `BrowserBufferBackend` (which used `#[test]` and never ran before), and two checking that IndexedDB page keys accept only whole numbers from 0 to 2^53. On `wasm32-wasip1` under Wasmtime: the unit and integration tests that do not use a file run, 935 passing; nine that spawn threads or a child process are ignored on WASI. These are not counted above.
+This covers the unreleased file-format-v8 work (#287, #371): the index-key value-collision fix, the v7→v8 migration, and the drop of formats v1–v6. It otherwise still covers the public database API, the Datalog engine, storage and recovery paths, v2.0.0's locking and structured-error-code changes, and v2.0.1's regression test for rebuilding indexes on open after several checkpoints (#370). Merged from the v2.x line: `tests/point_query_history_test.rs` and new storage unit tests check that attribute-narrowed bound-entity lookups return exactly what a full scan returns, and that `net_asserted_facts` matches its previous implementation on randomized histories (#323). Attribute-scan tests check that the AEVT range covers exactly the queried attribute, including non-ASCII names such as `:丿` and prefix siblings such as `:ab` for `:a` (#381). Incremental B+tree rebuild tests check that checkpoints which copy untouched index leaves produce exactly the entries and file checksum a full rebuild would, including over repeated checkpoints, that single-fact checkpoints do not fragment the index, and that a damaged slot directory is rejected rather than copied (#315). B+tree cursor tests check that every scan walks the tree, not the leaf `next_leaf` chain: full scans and start positions match the input, `seek` from the current position lands where a fresh descent from the root would (randomized, plus within a leaf, to a sibling, across subtrees, past the end, into the gap after a leaf, and backwards as a no-op), a seek to the sibling leaf reads exactly one page, reads are unchanged with every `next_leaf` zeroed, a child pointer into a non-B+tree page is STG-013, and a cycle in child pointers is an error, not a hang (v8 storage format PR 1, #374). Directory-sync unit tests check that creating the `.graph` file or the WAL, and deleting the WAL, fsync the parent directory after the file operation, and that reopening an existing file does not (#389). Disjunction tests check that `or-join` returns an empty result, not INT-031, when no rows reach it: on an empty database, after a pattern that matches nothing, after a `not` that removes every row, and in a rule body (#405). A stratification unit test builds the same two-rule negative cycle 64 times and checks that the INT-054 message names the same predicate pair every time (#410). Magic-sets tests check that a recursive rule with a literal start that recurses through another rule returns the same results as without the literal (#297). API tests check that `execute()` and `WriteTransaction::execute()` reject `$slot` bind tokens in every position with API-010 (#407). The REPL `run()` test now runs in a child process with null stdin, so it no longer hangs when the test runner's stdin is an open non-TTY stream (#415). v8 page-format tests (PR 2, #374, #388) check the 24-byte page header (a flipped bit, a wrong page id and a future generation each give their own STG code, legacy page types fail before the CRC, and a failed page is never cached), meta-page encoding, the free-list chain, WAL v2's base generation, and every row of the meta-selection table: both slots valid, a torn newest slot with the WAL's base generation (opens at the older one), a WAL newer than the valid meta, pages of the next generation on the free list or past `page_count` with no WAL (all STG-033, with the file unmodified), an unknown feature bit (STG-034), and a pre-release v8 single header (STG-032). Fault-injection tests crash `save()` at every page write (cleanly and with torn pages, including the meta write) and every sync, and crash a v7 migration at every write; each reopen finds exactly the old or the new checkpoint, and every reachable page plus the free list covers the file exactly. Twenty-five consecutive saves never write a page the previous meta references. Covering-key tests (PR 3, #433) check that byte order equals logical order for every key component and value type on random tuples (negative, zero and large integers, NaN and ±0.0, strings with 0x00, 64- and 65-byte strings, FOREVER, newest-transaction-first) and that every component round-trips; that prefix-compressed leaves and shortest-separator internal nodes round-trip, agree with a linear scan, keep `max(left) < s ≤ min(right)`, and reject an overflow; that the byte-key B+tree's builds, incremental rebuilds, cursor and `seek` match their expected sets; that dictionary ids are assigned once, never reused, shared between a keyword attribute and value, and deterministic; that a re-asserted or retracted long value writes no new value page and a forced hash collision still finds the right value; that one transaction with two timestamps is STG-037 and a missing dictionary entry STG-036; that committed reads by entity, entity and attribute, attribute, and in full equal an in-memory model across eight checkpoints and a reopen; that short-valued reads touch no value page; that a v7 file with every value type, long strings, refs and retractions migrates to exactly the same facts; that a pre-covering-key v8 file is STG-032; and that string values over 4,068 bytes and attributes or keywords over 1,024 bytes are WAL-003. A WAL test checks that reopening next to a fully checkpointed WAL does not reuse transaction numbers (#447). Copy-on-write checkpoint tests (PR 4, #434) check that lazy free-list pops and pushes conserve every page across page boundaries, partial head pages and chain exhaustion, never hand out a page freed in the same generation, and share unread chain pages unchanged; that a copy-on-write insert equals a sorted merge for random batches (including keys below the first and above the last, many into one leaf, root growth to depth 3, and 1 KB separators that split internal nodes), leaves the old tree readable and unchanged, frees exactly the replaced nodes, writes only new pages, writes exactly one leaf and two internal nodes for one entry in a depth-3 tree, and does not fragment leaves under single inserts; that a checkpoint after 1 or 100 right-edge facts writes at most the tree-depth difference more pages at 100,000 facts than at 10,000, and at most one path per new entry per tree for random keys; and that four reader threads querying throughout 40 checkpoints never fail and never see the fact count go backwards. Hardening tests (PR 5) damage an index leaf, an internal node, a dictionary leaf, a value page and a free-list page in turn. Every committed read or checkpoint that reaches the damaged page fails with STG-029, never with wrong or fewer rows. A query through `Minigraf` on a file with damaged leaves fails with STG-029, and the file still opens at its last checkpoint. A size test measures at most 200 bytes per fact (142 measured) on 144k facts in #433's shape; its 1.15M-fact variant is ignored locally and runs in the nightly smoke workflow. A shared dictionary-cache test checks that cached ident and timestamp lookups return the same facts and that the cache stays bounded. Merged from the v2.x line: storage and `edge_cases_test.rs` tests check that more than 65,535 uncheckpointed facts each resolve to their own fact through entity lookups and attribute scans, in memory and file-backed (#445). Merged from the v2.x line: `tests/golden_corpus_test.rs` opens a copy of each committed golden file in `tests/golden/` (v7 files written by minigraf 2.0.3: one checkpoint, several checkpoints, indexes rebuilt on open, a crash-left WAL, an already-checkpointed WAL, same-transaction multi-values) and checks its manifest's CRC32, `tx_count` and query results after open, after a checkpoint and reopen, and after one more write; a second test checks that every golden file has a manifest (#391). On `v3` the same test checks that each v7 file has a v8 meta page after its first open and gives the same results after reopening the migrated file, and adds seven v8 golden files (one checkpoint, seven copy-on-write checkpoints, a crash-left v2 WAL, an already-checkpointed v2 WAL, same-transaction multi-values, a v7 file migrated in place, and long values at the size limits); the #371 queries, skipped on v2.x, run and pass. Integrity tests (#373) check that intact files verify with no problems and an exact fact and page count, and that `verify` reports each kind of damage with its code: an EAVT, AEVT, AVET or VAET leaf missing an entry (STG-038), keys out of order and a page reached from two trees (STG-039), a rotted index leaf (STG-029), a free page still in use and a leaked page (STG-035), a missing transaction entry (STG-036), and an entity id whose UUID maps to another id (STG-040). After each index or free-list damage, `rebuild_indexes` leaves a file that verifies clean, reads back every fact and accounts for every page. The source is an index that agrees with another one, or the only intact one; three intact indexes that all disagree, or a damaged dictionary, give STG-041 with the file unchanged. A rebuild commits pending facts, including new ids and long values. A crash at every write (clean and torn) and every sync of a rebuild reopens either at the old generation with only its old damage or at the new one with none, never losing a fact. Through `Minigraf` (`tests/integrity_test.rs`), a rebuild commits WAL entries and deletes the WAL, and flipping a byte in each leaf of a file in turn is always reported, then either repaired (index leaves) or refused with STG-041 and the file unchanged (dictionary leaves). Live-read tests (#379) check that `triple_len` ends exactly where `tx↓` begins for every value type and index; that on random histories (several valid-time windows, retractions, re-assertions, several values per attribute, long values, 12 transactions per checkpoint) the committed live read for every scan kind and `:as-of` point is exactly the net-asserted set, that it stays equivalent with pending facts on top, and after reopen; and that a point read on a triple asserted and retracted 2,000 times reads under a third of the pages a history read does, with or without `:as-of`. `tests/live_reads_test.rs` runs the same history in a checkpointed file database and in memory and checks that point, attribute, full-scan, join, valid-time, `:as-of` and rule queries return the same rows, before and after reopen. One-window tests (#435) check that `net_asserted_facts` keeps each triple's newest transaction only (a later window replaces an earlier one, closing an open window, a retraction in the newest transaction hides it, records with two windows in one transaction keep both, once each) against a per-triple model on random histories; that the on-disk key walk agrees at every `:as-of` before and after reopen; and that `API-011` rejects two windows of one fact in one transaction without taking a `tx_count`. `tests/valid_time_window_test.rs` checks replacing, closing, extending, reopening and retract-then-reassert through entity-bound and attribute queries in memory, on a checkpointed file and after reopen, and `API-011` from `transact` and from `WriteTransaction::commit`. Cursor tests (#432, `tests/cursor_test.rs`) check that `query()` batches partition the `execute()` answer for several batch sizes (never empty, never over `max_rows`, `max_rows == 0` still progresses, `None` stays `None`), that the iterator and aggregates, rules, `:as-of` and `:any-valid-time` match `execute()`, that a cursor opened before a `transact`, a `WriteTransaction` commit, a retract or a checkpoint returns the pre-write answer to the end (in memory and file-backed), that `transact`/`retract`/`rule` are `API-012` and bind slots `API-010`, that a `WriteTransaction` thread gets `INT-001`, that rule limits give `INT-020` as from `execute()`, that `PreparedQuery::query` matches `PreparedQuery::execute`, and that a cursor is `Send` and outlives its database handle. Fact-log tests (#430, `tests/fact_log_test.rs`) check that `fact_log()` returns exactly the records written (assertions and retractions, with `tx_count` and `tx_id`) in memory, with everything pending, half checkpointed, fully checkpointed and after reopen, in both orders, with windows of 1 to 1,000 records and batch sizes of 1 to 1,000, in non-decreasing `tx_count` in Tx order; that every layout gives identical records, including valid-time windows and long string values; that a transaction larger than the window is split with no loss or duplicate; that attribute, attribute-prefix, entity and tx-range filters and their combinations match a model, and unknown names match nothing; that writes after open are not in the log; that `checkpoint()` and `rebuild_indexes()` are `API-013` while a log is open (a checkpoint with nothing to write is allowed), that automatic checkpoints from `execute()` and `WriteTransaction::commit` wait for the log, and that closing, dropping or finishing the log releases the database; that a `WriteTransaction` thread gets `INT-001`; and that a log is `Send`, outlives its database handle, and the deferred writes replay on the next open. Read-only open tests (#429, `tests/read_only_open_test.rs`) check that a read-only handle on a file with checkpointed facts and a pending WAL returns the same query results, `tx_count` and fact log as a read-write open; that queries, a cursor, a fact log, `verify`, `prepare`, rules and a UDF leave the `.graph` and WAL bytes and the `.graph` mtime unchanged, and no WAL is created; that `transact`, `retract`, `begin_write`, `checkpoint` and `rebuild_indexes` are `API-014` without taking a `tx_count`, also on a read-only in-memory database and through the builder path; that a missing file is `STG-042` and nothing is created; that an empty file is an empty database and stays 0 bytes; that read-only handles share a file while a read-write one is refused with `STG-025`, both ways; that a file without write permission opens read-only; and that small and whole-file page caches work. File-backend unit tests check that a shared-mode backend refuses page writes and syncs with `INT-056`, that the in-process registry counts readers and admits readers or one writer (also without kernel locks), and that a reader in another process shares the file with a reader here and refuses a writer here with `STG-026`. Storage unit tests check that a read-only open of a v7 file at every point of an interrupted migration (clean and torn writes) sees every fact and writes nothing, and that an empty backend stays empty. `tests/golden_corpus_test.rs` opens a copy of every golden file read-only first and checks its `tx_count` and queries, and that neither the file nor its WAL changes. Log-writer tests (#431, `tests/log_writer_test.rs`) copy a source's fact log (assertions, retractions, an explicit valid-time window, long strings, refs, keywords, checkpointed and pending facts) through `LogWriter` and check that the new file has no `.partial` or WAL, verifies clean, and gives the source's `tx_count`, fact log and query results (current, `:valid-at`, `:any-valid-time`, every `:as-of`, and entity-, attribute- and value-bound lookups) read-write, read-only and after reopen (#370); that it takes new writes at the source's next `tx_count`; that 90,000 facts over two batch commits verify clean and count correctly at `:as-of`; that a purged middle transaction is a hole whose `:as-of` equals the one before, and trailing holes keep the counter through `advance_tx_count`; that an empty log is an empty database with the counter; that `tx_count` 0, a lower or closed transaction and a backwards advance are `API-015`, a second `tx_id` `API-016`, a second window `API-011` and oversize values or idents `WAL-003`, each leaving the writer usable and the output exact, with repeats written once; that an existing target or WAL is `STG-043`, a second writer `STG-025` and `read_only` `API-014`; that a stale `.partial` is reused; that dropping an unfinished writer leaves nothing; that `finish` refuses a target created during the build and leaves it untouched; and that `LogWriter` is `Send`. Unit tests check that a batch commits only when a transaction opens past the batch size, never splitting one, and that `FileBackend::truncate` empties a file. A unit test in `error.rs` checks that `MinigrafError::invalid_argument` and `MinigrafError::closed`, the constructors for language bindings, give API-017 and API-018 with their text. Three `BrowserDb` tests (wasm32, run with `wasm-bindgen-test` in a browser, not counted above) check that `query()` batches of 1, 7 and 1,000 give the rows of `execute()`, that a cursor keeps the answer from when it opened and returns the end after `close()`, and that a `transact` is API-012. The wasm32 targets run in CI (`.github/workflows/wasm.yml`). In a browser (`wasm-pack test --headless`, Firefox and Chrome): 25 `wasm_bindgen_test` tests: fourteen for `BrowserDb` (including IndexedDB persistence, the cursor, and the flush returning every dirty page and failing on one it cannot read, from #470), nine for `BrowserBufferBackend` (which used `#[test]` and never ran before), and two checking that IndexedDB page keys accept only whole numbers from 0 to 2^53. On `wasm32-wasip1` under Wasmtime: the unit and integration tests that do not use a file run, 935 passing; nine that spawn threads or a child process are ignored on WASI. These are not counted above.
 
 ### Covered Areas
 
diff --git a/src/browser/buffer.rs b/src/browser/buffer.rs
index 64958d95e..86376a390 100644
--- a/src/browser/buffer.rs
+++ b/src/browser/buffer.rs
@@ -43,6 +43,12 @@ impl BrowserBufferBackend {
     pub fn take_dirty(&mut self) -> HashSet<u64> {
         std::mem::take(&mut self.dirty)
     }
+
+    /// Mark `page_id` dirty without writing it, for tests of the flush path.
+    #[cfg(test)]
+    pub(crate) fn mark_dirty_for_test(&mut self, page_id: u64) {
+        self.dirty.insert(page_id);
+    }
 }
 
 impl Default for BrowserBufferBackend {
diff --git a/src/browser/mod.rs b/src/browser/mod.rs
index 8f63a30b7..8462facc8 100644
--- a/src/browser/mod.rs
+++ b/src/browser/mod.rs
@@ -487,6 +487,28 @@ mod tests {
 
     wasm_bindgen_test_configure!(run_in_browser);
 
+    #[wasm_bindgen_test]
+    fn take_dirty_pages_returns_written_pages() {
+        use crate::storage::StorageBackend;
+        let mut pfs = PersistentFactStorage::new(BrowserBufferBackend::new(), 0).unwrap();
+        let _ = pfs.with_backend_mut(|b| b.take_dirty());
+        pfs.with_backend_mut(|b| b.write_page(3, &[7u8; crate::storage::PAGE_SIZE]))
+            .unwrap();
+        let pages = take_dirty_pages(&mut pfs).expect("dirty pages");
+        assert_eq!(pages.len(), 1);
+        assert_eq!(pages[0].0, 3);
+        assert!(take_dirty_pages(&mut pfs).expect("second call").is_empty());
+    }
+
+    #[wasm_bindgen_test]
+    fn unreadable_dirty_page_is_an_error_not_skipped() {
+        let mut pfs = PersistentFactStorage::new(BrowserBufferBackend::new(), 0).unwrap();
+        // A dirty id with no page behind it: before the fix it was dropped
+        // from the flush and the caller still saw success.
+        pfs.with_backend_mut(|b| b.mark_dirty_for_test(99));
+        assert!(take_dirty_pages(&mut pfs).is_err());
+    }
+
     #[wasm_bindgen_test]
     async fn in_memory_transact_and_query() {
         let db = BrowserDb::open_in_memory().expect("open_in_memory");