ccusage-test-support

Test-only helpers: filesystem fixtures and environment-variable guards.

Owns

• Fixture and the fs_fixture! macro — build a temporary directory tree from a literal file map, so loader tests read real files instead of mocks.
• EnvVarGuard and EnvVarsGuard — set the data-directory variables an adapter reads and restore them when the test ends.
• zcode::create_fixture — create the representative ZCode SQLite schema and usage rows shared by adapter and unified report tests.

Every crate that has tests uses this as a dev-dependency; nothing depends on it at runtime.

Public surface

• EnvVarGuard
• EnvVarsGuard
• Fixture
• zcode::create_fixture

Depends on

• assert_fs
• jiff
• sqlite

Build layer

Built in the foundation Crane artifact layer, so a change here recompiles every adapter. It is a dev-dependency only, so it never reaches the shipped binary.