Broaden community end-to-end coverage across core workflows

[Shreyas582]

Scope

Expand community-edition E2E coverage beyond individual lanes to protect core workflows from regression.

Acceptance Criteria

• Add E2E tests for at least these paths: dry-run baseline flow, live fallback flow, live success path, evidence bundle verify flow, and profile/config precedence flow.
• Execute coverage on Linux and Windows in CI for critical flows.
• Include one package-level smoke E2E check using released artifacts in CI/release validation.
• Document test matrix and ownership in docs/CI_CD.md.
• Update CHANGELOG.md with delivered coverage expansion.