CRITICAL FIX: Repair broken installation

- Add missing psutil to requirements.txt (was causing ModuleNotFoundError)
- Change pip install -e . to pip install . in README (production vs dev install)
- Fix installation issue by using proper production install method

Tested: pip install . now works properly without hanging or missing dependencies

README.md

@@ -89,7 +89,7 @@ cd Fss-Mini-Rag
 python3 -m venv .venv
 source .venv/bin/activate    # Linux/macOS
 # .venv\Scripts\activate     # Windows
-pip install -e .
+pip install .
 ```
 
 **Step 2: Start Using**

requirements.txt

@@ -19,4 +19,7 @@ rich>=13.0.0
 PyYAML>=6.0.0
 
 # Text search utilities (lightweight)
-rank-bm25>=0.2.2
+rank-bm25>=0.2.2
+
+# System monitoring
+psutil