feat: Python porting workspace with reference data and parity audit

src/models.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+
+
+@dataclass(frozen=True)
+class Subsystem:
+    name: str
+    path: str
+    file_count: int
+    notes: str
+
+
+@dataclass(frozen=True)
+class PortingModule:
+    name: str
+    responsibility: str
+    source_hint: str
+    status: str = 'planned'
+
+
+@dataclass(frozen=True)
+class PermissionDenial:
+    tool_name: str
+    reason: str
+
+
+@dataclass(frozen=True)
+class UsageSummary:
+    input_tokens: int = 0
+    output_tokens: int = 0
+
+    def add_turn(self, prompt: str, output: str) -> 'UsageSummary':
+        return UsageSummary(
+            input_tokens=self.input_tokens + len(prompt.split()),
+            output_tokens=self.output_tokens + len(output.split()),
+        )
+
+
+@dataclass
+class PortingBacklog:
+    title: str
+    modules: list[PortingModule] = field(default_factory=list)
+
+    def summary_lines(self) -> list[str]:
+        return [
+            f'- {module.name} [{module.status}] — {module.responsibility} (from {module.source_hint})'
+            for module in self.modules
+        ]