Header of process and node ports follow each other both ways: a panel edit rewrites only the def line of edited code, a code save reads the header back into input ports and settings (draft and response); Space types in the node editor again

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx

docs/code/nodes.md

@@ -29,6 +29,24 @@ Inside a node, `import fluksio` exposes reporting and artifact helpers. It
 does not expose the engine's internal modules. Other imports come from the
 node's Python environment; see [Packages](#packages).
 
+## The header follows the ports
+
+On the canvas, the parameters of `process` and the node's input ports and
+settings are kept in step, in both directions.
+
+- Changing ports or settings in the node panel rewrites the
+  `def process(...)` line and leaves the rest of the code as it is. Input
+  ports come first, in their order, then the settings. A parameter that stays
+  keeps its annotation and default.
+- Saving the code reads that line back. A name the node already has keeps
+  its kind. A new parameter becomes a setting when it has a default, which
+  becomes its value, or when it comes after a setting. Any other new
+  parameter becomes an input port. Removing a parameter removes its port or
+  setting, and renaming a single one renames the port (keeping its message)
+  or the setting (keeping its value).
+- Shared code, code from `fluksio sync`, and a header with a decorator,
+  `*args`, `**kwargs`, a bare `*` or `/` are left alone in both directions.
+
 ## Producing values over time
 
 Yield dictionaries to publish outputs before the node finishes: