Documentation, comments and small changes

source/topology_renderer.py

@@ -24,6 +24,8 @@ from topology_plan import (
 )
 
 
+# =========================== Rendering helpers ===========================
+
 def _python_string(value: str) -> str:
     """Return a safe Python string literal.
 
@@ -187,6 +189,12 @@ def _render_gateway_configuration(interface: PlannedInterface) -> List[str]:
 def _render_service_start(service: PlannedService, index: int) -> List[str]:
     """Render startup code for one planned service.
 
+    Construct dnsmasq arguments from the resolved binding and DHCP settings,
+    using the service index for lease, PID, and log filenames.
+    Emit commands that remove previous lease and PID files, launch the daemon
+    in the background, and record its shell PID for later cleanup.
+    The emitted startup sequence does not check daemon readiness.
+
     Args:
         service: Fully resolved service operation.
         index: Stable service index used for temporary runtime files.
@@ -238,9 +246,18 @@ def _render_service_start(service: PlannedService, index: int) -> List[str]:
     ]
 
 
+# ============================ Public interface ============================
+
 def render_python(plan: ExecutionPlan) -> str:
     """Render an execution plan as a complete executable Python program.
 
+    Assemble source lines for runtime helpers and the network lifecycle.
+    Emit construction first so interfaces exist before configuration; emit
+    addresses before default routes and services that depend on them.
+    Finish with the interactive CLI and a finally block that attempts tracked
+    service cleanup followed by network shutdown.
+    Rendering itself only produces text and does not execute these operations.
+
     Args:
         plan: Fully resolved execution plan returned by topology_plan.plan().
 
@@ -377,6 +394,8 @@ def render_python(plan: ExecutionPlan) -> str:
     return "\n".join(lines)
 
 
+# =============================== Self-test ===============================
+
 def _self_test() -> None:
     """Run a smoke test against the public render_python() interface."""