refactor: organize pilot packages

Group review, feedback, evaluation, observability, and entrypoint code into packages. Keep thin top-level compatibility shims for existing scripts and imports, and mirror the structure in the tests.

pilot/review/ports.py

@@ -0,0 +1,17 @@
+"""Stable interfaces shared by the review pipeline and its adapters."""
+from __future__ import annotations
+
+from typing import Protocol
+
+
+class Forge(Protocol):
+    def get(self, path: str, accept: str = "application/json") -> tuple[int, bytes]: ...
+    def post(self, path: str, body: dict) -> tuple[int, bytes]: ...
+
+
+class Reviewer(Protocol):
+    def review(self, system: str, user: str, max_tokens: int) -> str: ...
+
+
+class Telemetry(Protocol):
+    def emit(self, **event: object) -> None: ...