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/backend/backend_parse_cli_args/backend_parse_cli_args.py

@@ -1,27 +1,37 @@
 """Workflow plugin: parse CLI arguments."""
+
 import argparse
 
+from ...base import NodeExecutor
 
-def run(runtime, inputs):
-    """Parse command line arguments.
 
-    Inputs:
-        args: Optional list of arguments (defaults to sys.argv)
-    """
-    parser = argparse.ArgumentParser(description="MetaBuilder Workflow")
+class ParseCliArgs(NodeExecutor):
+    """Parse command line arguments."""
 
-    parser.add_argument("--config", "-c", default="config.json",
-                       help="Path to configuration file")
-    parser.add_argument("--workflow", "-w",
-                       help="Path to workflow file")
-    parser.add_argument("--verbose", "-v", action="store_true",
-                       help="Enable verbose output")
-    parser.add_argument("--dry-run", action="store_true",
-                       help="Simulate workflow execution")
+    node_type = "backend.parse_cli_args"
+    category = "backend"
+    description = "Parse command line arguments"
 
-    args_list = inputs.get("args")
-    parsed = parser.parse_args(args_list)
+    def execute(self, inputs, runtime=None):
+        """Parse command line arguments.
 
-    runtime.context["cli_args"] = vars(parsed)
+        Inputs:
+            args: Optional list of arguments (defaults to sys.argv)
+        """
+        parser = argparse.ArgumentParser(description="MetaBuilder Workflow")
 
-    return {"success": True, "args": vars(parsed)}
+        parser.add_argument("--config", "-c", default="config.json",
+                           help="Path to configuration file")
+        parser.add_argument("--workflow", "-w",
+                           help="Path to workflow file")
+        parser.add_argument("--verbose", "-v", action="store_true",
+                           help="Enable verbose output")
+        parser.add_argument("--dry-run", action="store_true",
+                           help="Simulate workflow execution")
+
+        args_list = inputs.get("args")
+        parsed = parser.parse_args(args_list)
+
+        runtime.context["cli_args"] = vars(parsed)
+
+        return {"success": True, "args": vars(parsed)}

workflow/plugins/python/backend/backend_parse_cli_args/factory.py

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

workflow/plugins/python/backend/backend_parse_cli_args/package.json

@@ -6,8 +6,11 @@
   "license": "MIT",
   "keywords": ["backend", "workflow", "plugin", "cli", "args"],
   "main": "backend_parse_cli_args.py",
+  "files": ["backend_parse_cli_args.py", "factory.py"],
   "metadata": {
     "plugin_type": "backend.parse_cli_args",
-    "category": "backend"
+    "category": "backend",
+    "class": "ParseCliArgs",
+    "entrypoint": "execute"
   }
 }