Per-test overrides in configuration

[MatthewMckee4]

Allow overriding settings for specific tests or test sets using filter expressions in configuration:

[[profile.default.overrides]]
filter = "tag(slow)"
timeout = "300s"
retry = 3

[[profile.default.overrides]]
filter = "tag(database)"
test-group = "database"
threads-required = 2

[[profile.default.overrides]]
filter = "test(~integration)"
slow-timeout = "30s"

Overrides are applied in order, so later entries take precedence. This is the glue that connects many other features (timeouts, retries, test groups) to specific tests.

See: https://nexte.st/docs/configuration/per-test-overrides/