Refactor investor and fund schemas to support new check size range

- Removed deprecated `stage_focus` column from `InvestorTable` and `InvestorSchema`.
- Updated `FundTable` to change `fund_size` from VARCHAR to INTEGER and added `check_size_lower` and `check_size_upper` columns.
- Modified API routes to return investor-fund combinations as separate entries.
- Created new `InvestorFundData` schema for combined investor-fund responses.
- Implemented LLM parsing for check size range from estimated investment size.
- Updated database migration script to reflect schema changes and ensure data integrity.
- Removed obsolete verification and test scripts related to the old schema.

app/services/querying.py

@@ -95,6 +95,7 @@ class QueryProcessor:
                     selectinload(InvestorTable.portfolio_companies),
                     selectinload(InvestorTable.team_members),
                     selectinload(InvestorTable.sectors),
+                    selectinload(InvestorTable.funds),
                 )
                 .filter(InvestorTable.id.in_(investor_ids))
             )
@@ -109,6 +110,7 @@ class QueryProcessor:
                     portfolio_companies=investor.portfolio_companies,
                     team_members=investor.team_members,
                     sectors=investor.sectors,
+                    funds=investor.funds,
                 )
                 investor_data_list.append(investor_data)