Stock Prices - Supply and Demand

STOCK PRICES - SUPPLY AND DEMAND 1.1.0 - CHANGELOG
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This release wires the money supply to SDM Economy. Until now the inflation factor was
driven only by physical currency items in the world; now banked wealth counts too.

SDM ECONOMY: ACCOUNT BALANCES IN THE MONEY POOL
- With SDM Economy installed, the market totals every player's account balance, server-wide,
  and adds it to the money pool. The more money pooled across everyone's accounts, the higher
  every price drifts; spend or drain those accounts and prices ease back down.
- This is ADDED on top of the physical-currency denominations, not a replacement. Coins in
  pockets and credits in the bank now inflate the market together.
- Locked (not-yet-unlocked) currencies are skipped, since that balance is not usable money.

NEW CONFIG
- [currency] sdmCurrencies: choose which SDM currencies count and what each is worth, as
  '<currencyName>=<value in base units>' entries. Leave it EMPTY (the default) to count every
  SDM currency at face value, where one unit equals one base unit. Add entries to whitelist
  only the real-money currencies, or to convert currencies that aren't worth one base unit each.
- [integration] sdmEnabled (already present, default on) now actually drives the read; with it
  off, or with SDM Economy absent, the money pool falls back to physical currency exactly as before.

UNDER THE HOOD
- SDM Economy is a soft dependency: detected at runtime and never bundled. Servers without it
  are completely unaffected. If an SDM read ever fails, the market logs it once and leaves the
  inflation factor neutral rather than interrupting the daily recompute.

Everything from 1.0.0 is unchanged: the symmetric pricing model, the four forces, the Market
keybind screen, Spud's Shop SRP stalls, smart bills, the commodity model, and the commands.