Add Skill: text-concatenation

Extracted from: https://github.com/temiroff/Blacknode.git
Score: 1.0

skills/text-concatenation/metadata.json

@@ -0,0 +1,32 @@
+{
+  "name": "text-concatenation",
+  "version": "1.0.0",
+  "goal": "Concatenate two text inputs using Blacknode node graph",
+  "inputs": [
+    "text_a",
+    "text_b"
+  ],
+  "steps": [
+    "Create a Blacknode Graph instance",
+    "Add a Text node with param value set to text_a",
+    "Add a second Text node with param value set to text_b",
+    "Add a Concat node that accepts inputs 'a' and 'b' and outputs 'value'",
+    "Add an Output node with input port 'value'",
+    "Connect first Text node 'value' port to Concat 'a' port",
+    "Connect second Text node 'value' port to Concat 'b' port",
+    "Connect Concat 'value' port to Output 'value' port",
+    "Invoke graph cook on Output 'value' to evaluate and return result"
+  ],
+  "outputs": [
+    "concatenated_text"
+  ],
+  "failure_modes": [
+    "Port name mismatch causes connection error",
+    "Missing runtime or graph not initialized",
+    "Cook on nonexistent node returns error"
+  ],
+  "confidence": 0.9,
+  "explanation": "The repo contains example converted workflows; converted_text_pipeline.py demonstrates a simple reusable pattern of two source nodes feeding a concatenation node into an output, applicable to any string joining task in Blacknode.",
+  "source_repo": "https://github.com/temiroff/Blacknode.git",
+  "score": 1.0
+}