Function analyze_sidecars 

pub fn analyze_sidecars(dir: Option<&Path>) -> String

Collect sidecar JSON files and return the full gauntlet analysis.

When dir is Some, reads sidecars from that directory. Otherwise uses the default sidecar directory (KTSTR_SIDECAR_DIR override, or {CARGO_TARGET_DIR or "target"}/ktstr/{kernel}-{project_commit}/, where {project_commit} is the project HEAD short hex with -dirty when the worktree differs).

Returns the concatenated output of analyze_rows, verifier stats, callback profile, and KVM stats. Returns an empty string when no sidecars are found.