fix(semantic_extract): Pass API key to Groq LLM provider in extraction methods

- Add API key handling in extract_entities_llm(), extract_relations_llm(), and extract_triplets_llm()
- Add explicit api_key handling in NERExtractor and RelationExtractor
- Add llm_model parameter support in extract_triplets_llm() for consistency
- Fix relation extraction bug with type checking for subject_text/object_text
- Add environment variable fallback for API keys
- Update notebook with standard API key pattern

Fixes #147

cookbook/use_cases/finance/03_Earnings_Call_Analysis.ipynb

@@ -73,11 +73,28 @@
     "from semantica.llms import Groq\n",
     "import os\n",
     "\n",
-    "GROQ_API_KEY = \"\"\n",
+    "# Set your Groq API key here or as an environment variable\n",
+    "# Option 1: Set environment variable (recommended): export GROQ_API_KEY=\"your-api-key-here\"\n",
+    "# Option 2: For Google Colab: from google.colab import userdata; GROQ_API_KEY = userdata.get(\"GROQ_API_KEY\")\n",
+    "# Option 3: Set directly below (not recommended for production)\n",
+    "GROQ_API_KEY = os.getenv(\"GROQ_API_KEY\", \"\")\n",
+    "\n",
+    "if not GROQ_API_KEY:\n",
+    "    try:\n",
+    "        from google.colab import userdata\n",
+    "        GROQ_API_KEY = userdata.get(\"GROQ_API_KEY\", \"\")\n",
+    "    except ImportError:\n",
+    "        pass\n",
+    "\n",
+    "if not GROQ_API_KEY:\n",
+    "    raise ValueError(\"GROQ_API_KEY not found. Please set it as an environment variable or update this cell.\")\n",
+    "\n",
+    "os.environ[\"GROQ_API_KEY\"] = GROQ_API_KEY\n",
     "    \n",
     "groq_llm = Groq(\n",
-    "        model=\"llama-3.1-8b-instant\",\n",
-    "        api_key=os.getenv(\"GROQ_API_KEY\", GROQ_API_KEY))\n",
+    "    model=\"llama-3.1-8b-instant\",\n",
+    "    api_key=GROQ_API_KEY\n",
+    ")\n",
     "\n",
     "print(f\"✓ Groq LLM initialized: {groq_llm.model}\")\n"
    ]
@@ -216,6 +233,7 @@
    "source": [
     "# Step 3: Extract entities using NERExtractor with Groq\n",
     "from semantica.semantic_extract import NERExtractor\n",
+    "import os\n",
     "\n",
     "text_for_extraction = parsed_doc[\"full_text\"]\n",
     "\n",
@@ -224,7 +242,8 @@
     "    provider=\"groq\",\n",
     "    llm_model=\"llama-3.1-8b-instant\",\n",
     "    min_confidence=0.5,\n",
-    "    temperature=0.0\n",
+    "    temperature=0.0,\n",
+    "    api_key=os.getenv(\"GROQ_API_KEY\")\n",
     ")\n",
     "\n",
     "entity_types = [\n",
@@ -324,6 +343,7 @@
    "source": [
     "# Step 5: Extract relationships using RelationExtractor with Groq LLM\n",
     "from semantica.semantic_extract import RelationExtractor\n",
+    "import os\n",
     "\n",
     "if not entities:\n",
     "    print(\"⚠️  No entities found. Skipping relationship extraction.\")\n",
@@ -339,7 +359,8 @@
     "            \"COMPARED_TO\", \"INCREASED_BY\", \"DECREASED_BY\", \"CHANGED_BY\",\n",
     "            \"DURING\", \"IN_QUARTER\", \"FOR_PERIOD\",\n",
     "            \"RELATED_TO\", \"PART_OF\", \"AFFECTS\"\n",
-    "        ]\n",
+    "        ],\n",
+    "        api_key=os.getenv(\"GROQ_API_KEY\")\n",
     "    )\n",
     "\n",
     "    relationships = relation_extractor.extract_relations(\n",
@@ -408,6 +429,7 @@
    "source": [
     "# Step 6: Extract RDF triplets using TripletExtractor with Groq LLM\n",
     "from semantica.semantic_extract import TripletExtractor\n",
+    "import os\n",
     "\n",
     "if not entities:\n",
     "    print(\"⚠️  No entities found. Skipping triplet extraction.\")\n",
@@ -417,16 +439,17 @@
     "    triplet_extractor = TripletExtractor(\n",
     "        method=\"llm\",\n",
     "        include_temporal=True,\n",
-    "        include_provenance=True\n",
+    "        include_provenance=True,\n",
+    "        provider=\"groq\",\n",
+    "        llm_model=\"llama-3.1-8b-instant\",\n",
+    "        temperature=0.0,\n",
+    "        api_key=os.getenv(\"GROQ_API_KEY\")\n",
     "    )\n",
     "\n",
     "    triplets = triplet_extractor.extract_triplets(\n",
     "        text_for_extraction,\n",
     "        entities=entities,\n",
-    "        relations=relationships if relationships else None,\n",
-    "        provider=\"groq\",\n",
-    "        llm_model=\"llama-3.1-8b-instant\",\n",
-    "        temperature=0.0\n",
+    "        relations=relationships if relationships else None\n",
     "    )\n",
     "\n",
     "    if hasattr(triplet_extractor, 'triplet_validator'):\n",