security: Pin dependencies to prevent supply chain attacks

- Pin all dependencies to specific versions
- Prevents transitive dependency vulnerabilities

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

Author: Mullassery

pyproject.toml

@@ -1,13 +1,13 @@
 [build-system]
-requires = ["setuptools>=65.0", "wheel", "maturin>=1.0,<2.0"]
+requires = ["setuptools==65.0", "wheel", "maturin==1.0,<2.0"]
 build-backend = "maturin.build"
 
 [project]
 name = "pyvectorhound"
 version = "1.0.0"
 description = "Diagnostic tool for vector search failures in RAG and LLM systems. Evaluate embedding quality, analyze vector search rank correlation, benchmark BM25 vs semantic search, profile reranker performance. Identify root cause of retrieval failures."
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = "==3.8"
 license = { text = "MIT" }
 authors = [{ name = "Georgi Mammen Mullassery", email = "mullassery@gmail.com" }]
 maintainers = [{ name = "Georgi Mammen Mullassery", email = "mullassery@gmail.com" }]
@@ -56,24 +56,24 @@ classifiers = [
 ]
 
 dependencies = [
-    "numpy>=1.20.0",
-    "requests>=2.28.0",
+    "numpy==1.20.0",
+    "requests==2.28.0",
 ]
 
 [project.optional-dependencies]
-qdrant = ["qdrant-client>=2.0.0"]
-chroma = ["chromadb>=0.4.0"]
-milvus = ["pymilvus>=2.3.0"]
-weaviate = ["weaviate-client>=3.0.0"]
-postgres = ["psycopg2-binary>=2.9.0"]
-pgvector = ["psycopg2-binary>=2.9.0"]
+qdrant = ["qdrant-client==2.0.0"]
+chroma = ["chromadb==0.4.0"]
+milvus = ["pymilvus==2.3.0"]
+weaviate = ["weaviate-client==3.0.0"]
+postgres = ["psycopg2-binary==2.9.0"]
+pgvector = ["psycopg2-binary==2.9.0"]
 dev = [
-    "pytest>=7.0.0",
-    "pytest-cov>=4.0.0",
-    "mypy>=1.0.0",
-    "black>=23.0.0",
-    "ruff>=0.1.0",
-    "maturin>=1.0.0",
+    "pytest==7.0.0",
+    "pytest-cov==4.0.0",
+    "mypy==1.0.0",
+    "black==23.0.0",
+    "ruff==0.1.0",
+    "maturin==1.0.0",
 ]
 all = [
     "pyvectorhound[qdrant,chroma,milvus,weaviate,postgres,pgvector,dev]",