refactor(workflow): convert all plugins to class/struct + factory pattern

- Python: class extending NodeExecutor + factory.py (80+ plugins)
- TypeScript: class implements NodeExecutor + factory.ts (7 groups, 116 classes)
- Go: struct with methods + factory.go (36 plugins)
- Rust: struct impl NodeExecutor trait + factory.rs (54 plugins)
- Mojo: struct + factory.mojo (11 plugins)

All package.json files now include:
- files array listing source files
- metadata.class/struct field
- metadata.entrypoint field

This enables a unified plugin loading system across all languages
with no import side effects (Spring-style DI pattern).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

workflow/plugins/python/control/control_switch/control_switch.py

@@ -1,11 +1,32 @@
 """Workflow plugin: switch/case control flow."""
 
+from ...base import NodeExecutor
 
-def run(_runtime, inputs):
+
+class ControlSwitch(NodeExecutor):
     """Switch on value and return matching case."""
-    value = inputs.get("value")
-    cases = inputs.get("cases", {})
-    default = inputs.get("default")
 
-    result = cases.get(str(value), default)
-    return {"result": result, "matched": str(value) in cases}
+    node_type = "control.switch"
+    category = "control"
+    description = "Switch/case control flow"
+
+    def execute(self, inputs, runtime=None):
+        """Switch on value and return matching case.
+
+        Args:
+            inputs: Dictionary with keys:
+                - value: The value to switch on
+                - cases: dict - Map of case values to results
+                - default: Default value if no case matches
+
+        Returns:
+            Dictionary with:
+                - result: The matched case value or default
+                - matched: bool - Whether a case was matched
+        """
+        value = inputs.get("value")
+        cases = inputs.get("cases", {})
+        default = inputs.get("default")
+
+        result = cases.get(str(value), default)
+        return {"result": result, "matched": str(value) in cases}

workflow/plugins/python/control/control_switch/factory.py

@@ -0,0 +1,7 @@
+"""Factory for ControlSwitch plugin."""
+
+from .control_switch import ControlSwitch
+
+
+def create():
+    return ControlSwitch()

workflow/plugins/python/control/control_switch/package.json

@@ -1,13 +1,16 @@
 {
   "name": "@metabuilder/control_switch",
   "version": "1.0.0",
-  "description": "control_switch plugin",
+  "description": "Switch/case control flow",
   "author": "MetaBuilder",
   "license": "MIT",
   "keywords": ["control", "workflow", "plugin"],
   "main": "control_switch.py",
+  "files": ["control_switch.py", "factory.py"],
   "metadata": {
     "plugin_type": "control.switch",
-    "category": "control"
+    "category": "control",
+    "class": "ControlSwitch",
+    "entrypoint": "execute"
   }
 }