[e54-bot]

Summary

Fixes #1028 — session-construction diagnostics now drive CLI exits by their declared Diagnostic.class instead of a hardcoded usage exit.

• session/registry.rs: lint-rule-error splits by RuleRegistryError kind — Io (missing/unreadable --rule-file) is Usage → exit 2; Rule/Catalog/DuplicateId (invalid content) stays SourceError → exit 1, per the owner decision's first option since the registry distinguishes the two.
• lint_package.rs: activate_pinned declares each LintPackageError with its existing exit_class() — the taxonomy lint package already reports. Without this, honoring Diagnostic.class would have regressed bad package pins (lint-package-source, a usage error) from exit 2 to exit 1 through lint/serve.
• session.rs (new): session::refuse reports a construction diagnostic and returns diagnostic.class.exit_code(); run_configured and run_lookup use it, and serve::run exits by the class directly. No wrapper pins a fixed exit anymore.
• cli.rs: check and lookup accept repeatable --rule-file wired into SessionConfig.lint_rule_paths, matching lint/serve — required so all three surfaces reach the construction boundary the same way.
• Tests: lint-rule-error rows restored and pinned in check_failures.rs (missing → Usage, invalid → SourceError) and lookup_failures.rs; new tests/session_exits.rs drives missing and invalid rule files through check, lookup, and serve and asserts exits 2 and 1.

main.rs/tests/cli.rs were already over the repository size-guard limit, so the shared refusal path lives in src/session.rs and the new test in tests/session_exits.rs; main.rs nets −6 lines vs HEAD.

Verification

• cargo fmt --all -- --check — clean
• cargo clippy --workspace --all-targets --all-features -- -D warnings — clean
• cargo test --workspace --all-targets --all-features </dev/null — 74 test binaries pass, 0 failures (12 mock_provider tests ignored; they require the LPP_MOCK_PROVIDER pin)
• git diff --check — clean
• Focused: cargo test -p wright-cli --test session_exits, -p wright-driver --test check_failures, --test lookup_failures — all pass
• Mutation check (acceptance criterion): temporarily re-hardcoded run_configured's construction exit to exit::USAGE → session_construction_exits_follow_the_diagnostic_class failed as required; reverted.

Unverified

• The mutation check was applied to run_configured only; run_lookup and serve::run use the same class-derived path and are covered by the same test, but were not individually mutated.

[e54-bot]

Round-1 finding fixed in f951bb5: the newly added narrating comments are removed; code and assertions are unchanged. fmt, clippy -D warnings, and the three affected test targets pass. Ready for follow-up review.