build: add project configuration and environment template

.env.example

@@ -0,0 +1,28 @@
+# OpenAI API authentication (required)
+OPENAI_API_KEY=sk-...
+
+# Qdrant configuration
+QDRANT_URL=http://localhost:6333
+QDRANT_API_KEY=
+
+# Fixed models (not configurable per strategy)
+EMBEDDING_MODEL=text-embedding-3-small
+LLM_MODEL=gpt-4o-mini
+
+# Retrieval defaults
+TOP_K=5
+
+# LLM generation parameters
+TEMPERATURE=0.0
+MAX_TOKENS=1024
+
+# Chunking defaults
+CHUNK_SIZE=512
+CHUNK_OVERLAP=50
+
+# Semantic chunking parameters
+SEMANTIC_THRESHOLD=0.3
+SEMANTIC_MIN_CHUNK_SIZE=3
+
+# SQLite database path
+DATABASE_URL=sqlite:///./data/chunking_benchmark.db