from typing import Dict, Any, List


def build_execution_plan(manifest: Dict[str, Any]) -> List[Dict[str, Any]]:
    codex_lineage = manifest.get("codex_lineage", {})
    segments = codex_lineage.get("segments", [])

    if segments:
        plan = []
        for seg in segments:
            plan.append({
                "segment_id": seg.get("id", "unknown"),
                "start_line": seg.get("start", 0),
                "end_line": seg.get("end", 0),
                "start_byte": seg.get("start_byte", 0),
                "end_byte": seg.get("end_byte", 0)
            })
        return plan

    return [{
        "segment_id": "seg_0",
        "start_line": 0,
        "end_line": 0,
        "start_byte": 0,
        "end_byte": 0
    }]