feat(energy): surface coal and TTF gas spot prices in analyst context (#2715)

* feat(intelligence): surface coal and TTF gas spot prices in analyst context

- Add TTF=F (TTF Natural Gas) to scripts/shared/commodities.json after NG=F
- Add coalSpotPrice and gasSpotTtf fields to AnalystContext interface
- Add extractCommodityQuote and buildSpotCommodityLine helpers in chat-analyst-context.ts
- Derive coal (MTF=F) and TTF (TTF=F) from already-fetched commodities bootstrap, no extra Redis calls
- Gate on SPOT_ENERGY_DOMAINS (economic, geo, all)
- Register both fields in SOURCE_LABELS with CoalSpot/GasTTF labels
- Add coalSpotPrice and gasSpotTtf to DOMAIN_SECTIONS for geo and economic in chat-analyst-prompt.ts
- Push Coal Spot Price and TTF Gas Price sections into context when present

* fix(energy): use correct unit for Newcastle coal (/t not /MWh)

buildSpotCommodityLine hardcoded /MWh for all commodities. Coal is
priced per metric ton. Added denominator parameter with /MWh default,
pass /t for Newcastle coal.

shared/commodities.json

@@ -10,6 +10,7 @@
     { "symbol": "CL=F", "name": "Crude Oil WTI", "display": "OIL" },
     { "symbol": "BZ=F", "name": "Brent Crude", "display": "BRENT" },
     { "symbol": "NG=F", "name": "Natural Gas", "display": "NATGAS" },
+    { "symbol": "TTF=F", "name": "TTF Natural Gas", "display": "TTF GAS" },
     { "symbol": "RB=F", "name": "Gasoline RBOB", "display": "GASOLINE" },
     { "symbol": "HO=F", "name": "Heating Oil", "display": "HEATING OIL" },
     { "symbol": "URA", "name": "Uranium (Global X)", "display": "URANIUM" },