ADR-0052 moved success journaling out of the worker to the dispatch
layer, leaving the `source` that handlers threaded purely for the
worker's old history.log write dead. Remove it:
- drop `_source` from finalize_persistence and do_rebuild_from_text
- inline + delete the three read-only *_request wrappers
- drop the now-unused `source` param from the ~30 forwarding worker
handlers (leaf + composite), compiler-guided
- remove the `source` field from the DescribeTable/QueryData/RunSelect
requests and their DatabaseHandle methods (call sites updated)
The only worker `source` left is the snapshot/undo label
(snapshot_then / stage_pre_mutation / begin_batch). Purely mechanical,
no behaviour change. 2471 pass / 0 fail / 1 ignored, clippy clean.
Each top-level tests/*.rs was its own crate → its own binary, each
statically linking the bundled engine + every dep. 26 of them, so an
edit to the lib relinked all 26. Moved the 25 standalone files into
tests/it/ under one tests/it/main.rs (the pattern typing_surface
already uses); cargo auto-detects it as the `it` target. End state: 2
integration-test binaries instead of 26.
Result: target/debug/deps 1.5 GB → 629 MB (-58%). Build time barely
moved (clean 22.9s→22.4s, lib-edit relink 13.3s→12.4s) — wall-clock is
dominated by compiling, not linking, so this is a disk win, not a speed
win (see docs/plans/20260602-test-consolidation.md). Tests unchanged at
2151/0/1; clippy clean; no fixups needed. typing_surface_matrix stays
its own already-consolidated binary.
Tradeoff: the 25 files now share one crate (a compile error fails the
whole `it` binary; module-scoped namespaces, no clashes) — negligible
for a solo project.