Refactor investor and company management API with FastAPI integration

- Updated README.md to reflect new features and architecture.
- Implemented company management routes in app/api/companies.py.
- Enhanced main FastAPI application in app/main.py to include company routes and query processing.
- Improved querying capabilities in app/services/querying.py with natural language processing for investor searches.
- Updated requirements.txt to include necessary dependencies for FastAPI and related libraries.
- Added comprehensive error handling and response formatting for API endpoints.

app/main.py

@@ -1,23 +1,36 @@
 import io
 
 import pandas as pd
-from api import investors
+from api import companies, investors
 from db.db import db_dependency, init_database
 from fastapi import FastAPI, File, UploadFile
+from py_schemas import InvestorList
+from pydantic import BaseModel
 from services.openrouter import InvestorProcessor
 from services.querying import QueryProcessor
 
 app = FastAPI()
-app.include_router(investors.router)
 init_database()
 
 
+# Request models
+class QueryRequest(BaseModel):
+    question: str
+
+    class Config:
+        json_schema_extra = {
+            "example": {
+                "question": "Show me growth stage fintech investors in the US with check sizes over $1 million"
+            }
+        }
+
+
 @app.get("/")
-def read_root():
+def health():
     return {"Hello": "World"}
 
 
-@app.post("/parse-csv")
+@app.post("/parse-csv", tags=["CSV Upload"], response_model=list[dict])
 async def parse_csv(db: db_dependency, file: UploadFile = File(...)):
     # Read uploaded CSV with pandas
     content = await file.read()
@@ -28,16 +41,27 @@ async def parse_csv(db: db_dependency, file: UploadFile = File(...)):
     results = await processor.process_csv(df)
 
     # Convert Pydantic objects to dictionaries
-    return {"results": [r.dict() for r in results]}
+    return [r.model_dump() for r in results]
 
 
-@app.post("/query")
-async def query_investors(db: db_dependency, question: str):
+@app.post("/query", response_model=InvestorList, tags=["Querying"])
+async def query_investors(db: db_dependency, request: QueryRequest):
+    """
+    Query investors using natural language.
+
+    Supports queries like:
+    - "Show me seed stage investors"
+    - "Find fintech investors in Silicon Valley"
+    - "Growth stage investors with $5M+ check sizes"
+    - "Healthcare investors in Europe"
+    """
     processor = QueryProcessor(sql_session=db)
-    results = processor.process_query(question)
-    return {"results": results}
+    results = processor.process_query(request.question)
+    return results
 
 
+app.include_router(investors.router)
+app.include_router(companies.router)
 if __name__ == "__main__":
     import uvicorn