UI:
    future bill (like for health) when I click change should either get fancy and allow toggle, or at least just disable the text field with future in it

For bills:
    * estimate future bills/growth:
        [DONE] - calculate pragmatic min/avg/max/simple
        [DONE] - need to handle future only bills
        [DONE] - remove bills from Living_Expenses
        - fold future bills into calc so they are processed on the day of the bill 
            ==> need to factor in future bills based on events (such as health/phone when I quit), car when I settle it... 
            [DONE] ==> and remove hard-coded future costs (like Ioniq rego/ins) when we do above
        - inflation can then be put to a more realistic quarterly figure, and fix up Int Rate, again

    * might need to be able to mark a specific bill as an outlier - so we ignore the data somehow (think Gas is messing with my bills)
        - and even electricity, water, etc. for when we were away in Europe but mostly gas/elec

LONGER/HARDER:
    * need to work out 'first bill' and 'last bill' to auto-fill missing bills based on
      -- all missing bills follow varying growth models & its by choice -- therefore I need this in DB
         - ANN: flat, min, avg, max, manual
         - QTR: flat, qtrly seasonal: min/avg/max/manual, qtrly simple: min/avg/max/manual, annual: min/avg/max/manual
         - MON: flat, monthly: min/avg/max/manual, annual: min/avg/max/manual
      -- use this logic to add missing bills (date):
           -- ANN: missing annual bill, find date based on MM-DD and add new year - given we start with first_bill anyway, will only be used for future bill predictions
           -- QTR: missing quarterly bill, find date based on MM-DD and ??? - can have missing bilsl in first year
           -- MON: missing monthly bills, find date based on DD and put in each missing month 
      -- use this logic to add missing bills (amount):
           -- ANN: future only, so add ann_growth (based on drop-down) for each future year
           -- QTR: add growth (based on drop-down) for each future year
           -- MON: add growth (based on drop-down) for each future year 

MUCH LONGER/HARDER:
    potentially for each bill_type, there are unique extras - e.g. THIS feels too hard:
        water has 2 fixed charges (water & sewerage) and then a consumption charge (per ML)
        elec has 1 fixe charge (daily) and then consumption (per kwh) BUT, also daily solar rate
        gas has fixed charge and consumption
        internet, kayo is monthly fixed (but can go up sometimes)
        eweka is annual fixed
        phone is messier again.