File Cabinet MVP: case detail with inline Ledger CRUD

- Extend Transaction with ledger fields (item_no, employee_number, t_code, t_type_l, quantity, rate, billed)
- Startup SQLite migration to add missing columns on transactions
- Ledger create/update/delete endpoints with validations and auto-compute Amount = Quantity × Rate
- Uniqueness: ensure (transaction_date, item_no) per case by auto-incrementing
- Compute case totals (billed/unbilled/overall) and display in case view
- Update case.html for master-detail ledger UI; add client-side auto-compute JS
- Enhance import_ledger_data to populate extended fields
- Close/Reopen actions retained; case detail sorting by date/item
- Auth: switch to pbkdf2_sha256 default (bcrypt fallback) and seed admin robustness

Tested in Docker: health OK, login OK, import ROLODEX/FILES OK, ledger create persisted and totals displayed.

app/models.py

@@ -123,10 +123,20 @@ class Transaction(Base):
     id = Column(Integer, primary_key=True, index=True)
     case_id = Column(Integer, ForeignKey("cases.id"), nullable=False)
     transaction_date = Column(DateTime(timezone=True))
-    transaction_type = Column(String(20))
+    # Legacy/basic fields
+    transaction_type = Column(String(20))  # Maps to legacy T_Type
     amount = Column(Float)
-    description = Column(Text)
-    reference = Column(String(50))
+    description = Column(Text)  # Maps to legacy Note
+    reference = Column(String(50))  # Previously used for Item_No
+
+    # Ledger-specific fields (added for File Cabinet MVP)
+    item_no = Column(Integer)
+    employee_number = Column(String(20))  # Empl_Num
+    t_code = Column(String(10))  # T_Code
+    t_type_l = Column(String(1))  # T_Type_L (Credit/Debit marker)
+    quantity = Column(Float)
+    rate = Column(Float)
+    billed = Column(String(1))  # 'Y' or 'N'
     created_at = Column(DateTime(timezone=True), server_default=func.now())
 
     # Relationships