Fix Ruff CI failure by applying formatter output to flagged files

[Copilot]

The Lint (ruff) GitHub Actions job failed because ruff format --check detected formatting drift in four files while ruff check still passed. This PR aligns those files with the repository’s enforced Ruff formatting.

• Scope: formatting-only updates in CI-reported files

  • src/cairn/cli.py
  • src/cairn/db/flight.py
  • src/cairn/flight/ecs_routing.py
  • tests/integration/test_contradiction_tightening.py

• What changed

  • Applied Ruff’s canonical line wrapping/signature formatting.
  • No behavioral, API, or logic changes; diffs are limited to style normalization required by ruff format --check.

• Representative change pattern

# before
decision = decide_ecs_region(
    topo, ccloud_version=ccloud_version, preferred=preferred
)

# after
decision = decide_ecs_region(topo, ccloud_version=ccloud_version, preferred=preferred)