STEP-07-B: TicketResult Dataclass + ticket.result migration

[MrSnowNB]

STEP-07-B — TicketResult Dataclass

Part of: STEP-07 spec
Depends on: #2 (STEP-07-A)

What to build

Add TicketResult to src/operator_v7.py:

@dataclass
class TicketResult:
    outcome: str               # "pass" | "fail" | "error"
    elapsed_s: float = 0.0
    tokens: int = 0
    tool_calls: int = 0
    artifact_paths: List[str] = field(default_factory=list)
    reason: str = ""
    anchor: Dict[str, Any] = field(default_factory=dict)

Migrate ticket.result from Dict[str, Any] to Optional[TicketResult] in the Ticket dataclass. Update:

• to_dict() / from_dict() in operator_v7.py
• ticket_io.py YAML round-trip
• All write paths in agent/runner.py that assign to ticket.result

Invariant preserved

ticket.result defaults to None for backward compat with existing YAML files. Full round-trip lossless.

Gate

pytest tests/ -v still green after migration.

Files

• src/operator_v7.py
• src/ticket_io.py
• agent/runner.py