fix(security): update pyproject.toml langgraph and langchain to secure versions

- Updated langgraph>=0.1.0 to langgraph>=1.0.5 (fixes CVE-2025-8709)
- Updated langchain>=0.1.0 to langchain>=0.1.11 (fixes CVE-2024-28088)
- This was the missing piece causing security scanners to flag langgraph
  as high risk - pyproject.toml was allowing vulnerable versions

All dependency files now consistently specify secure minimum versions:
- requirements.txt: langgraph>=1.0.5, langchain-core>=1.2.6
- requirements.lock: langgraph==1.0.5, langchain-core==1.2.6
- requirements.docker.txt: langgraph>=1.0.5, langchain-core>=1.2.6
- pyproject.toml: langgraph>=1.0.5, langchain>=0.1.11

Author: T-DevH

pyproject.toml

@@ -23,8 +23,8 @@ dependencies = [
     "fastapi>=0.104.0",
     "uvicorn[standard]>=0.24.0",
     "pydantic>=2.0.0",
-    "langchain>=0.1.0",
-    "langgraph>=0.1.0",
+    "langchain>=0.1.11",  # Security: CVE-2024-28088 fixed in 0.1.11+. Note: We use langchain-core>=1.2.6 directly (includes CVE-2025-68664 fix)
+    "langgraph>=1.0.5",  # Security: CVE-2025-8709 fixed in 1.0.5+ (includes fix). Note: We use in-memory state (no SQLite checkpoint) as additional defense
     "psycopg[binary]>=3.1.0",
     "redis>=5.0.0",
     "pymilvus>=2.3.0",