feat: Propagate workflow plugins to Go, Rust, C++, and Mojo

Multi-language workflow plugin system following Python's structure:
- Each plugin in its own directory with implementation + package.json
- Category-level package.json manifests listing all plugins
- Consistent interface: run(runtime, inputs) -> outputs

Languages added:
- Go: math, string, logic, list, dict, var, convert (25+ plugins)
- Rust: math, string, logic, list, convert, var (50+ functions)
- C++: header-only math, string, logic, var, convert (30+ plugins)
- Mojo: math, string, list with systems programming features

Python structure fixed:
- Reorganized flat files into plugin subdirectories
- Added package.json metadata to all 120+ plugins
- Added missing backend category (15 plugins)
- Category manifests with plugin lists

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

workflow/plugins/python/math/math_abs/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_abs",
+  "version": "1.0.0",
+  "description": "math_abs plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_abs.py",
+  "metadata": {
+    "plugin_type": "math.abs",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_add/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_add",
+  "version": "1.0.0",
+  "description": "math_add plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_add.py",
+  "metadata": {
+    "plugin_type": "math.add",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_divide/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_divide",
+  "version": "1.0.0",
+  "description": "math_divide plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_divide.py",
+  "metadata": {
+    "plugin_type": "math.divide",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_max/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_max",
+  "version": "1.0.0",
+  "description": "math_max plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_max.py",
+  "metadata": {
+    "plugin_type": "math.max",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_min/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_min",
+  "version": "1.0.0",
+  "description": "math_min plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_min.py",
+  "metadata": {
+    "plugin_type": "math.min",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_modulo/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_modulo",
+  "version": "1.0.0",
+  "description": "math_modulo plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_modulo.py",
+  "metadata": {
+    "plugin_type": "math.modulo",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_multiply/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_multiply",
+  "version": "1.0.0",
+  "description": "math_multiply plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_multiply.py",
+  "metadata": {
+    "plugin_type": "math.multiply",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_power/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_power",
+  "version": "1.0.0",
+  "description": "math_power plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_power.py",
+  "metadata": {
+    "plugin_type": "math.power",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_round/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_round",
+  "version": "1.0.0",
+  "description": "math_round plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_round.py",
+  "metadata": {
+    "plugin_type": "math.round",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/math_subtract/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "@metabuilder/math_subtract",
+  "version": "1.0.0",
+  "description": "math_subtract plugin",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugin"],
+  "main": "math_subtract.py",
+  "metadata": {
+    "plugin_type": "math.subtract",
+    "category": "math"
+  }
+}

workflow/plugins/python/math/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@metabuilder/workflow-plugins-math",
+  "version": "1.0.0",
+  "description": "Mathematical operation plugins",
+  "author": "MetaBuilder",
+  "license": "MIT",
+  "keywords": ["math", "workflow", "plugins"],
+  "metadata": {
+    "category": "math",
+    "plugin_count": 10
+  },
+  "plugins": [
+    "math_abs",
+    "math_add",
+    "math_divide",
+    "math_max",
+    "math_min",
+    "math_modulo",
+    "math_multiply",
+    "math_power",
+    "math_round",
+    "math_subtract"
+  ]
+}