`decimal` is stored as exact TEXT, but SQLite has no native decimal type,
so arithmetic/aggregation implicitly coerces it to an IEEE-754 double.
The computed result carries no playground type, so `sum(price * qty)`
rendered the double's full noise — `298.59999999999997` for `298.60` — a
confusing, off-topic float lesson for a teaching tool.
Add `format_real_display`: round REAL values to 15 significant figures
(a double's reliable precision) then take the shortest round-tripping
form, collapsing `298.59999999999997` to `298.6`. Wired into `format_cell`
(result-set / `show data` cells) only — the sole surface where the noise
appears, since it arises from arithmetic.
Every other f64->string path keeps full precision for semantic, not
cosmetic, reasons: CSV persistence stays byte-exact for round-trip;
`render_value` is a canonical identity key for the uniqueness dry-runs
(dry_run_unique, check_uniqueness_collisions), where rounding would
report collisions the exact-valued engine wouldn't; FK-key matching and
EXPLAIN-SQL literals likewise stay exact.
ADR-0005 Amendment 1; +7 tests.
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.
claude@clouddev1