Variant/commodity (#1040)

* commod variants

* mining map layers complete

* metal news feed

* commod variant final

* readme update

* fix: clean up commodity variant for merge readiness

- Remove duplicate FEEDS definition (central feeds.ts is source of truth)
- Remove duplicate inline ALLOWED_DOMAINS in rss-proxy.js (use shared module)
- Add 14 commodity RSS domains to shared/rss-allowed-domains.json
- Remove invalid geopoliticalBoundaries property (not in MapLayers type)
- Fix broken mobile-map-integration-harness imports
- Remove Substack credit link from app header
- Rename i18n key commod → commodity
- Extract mineralColor() helper for DRY color mapping
- Add XSS-safe tooltips for mining sites, processing plants, commodity ports
- Add missing interface fields (annualOutput, materials, capacityTpa, annualVolumeMt)
- Comment out unused COMMODITY_MINERS export
- Isolate commodity DeckGL changes from unrelated basemap refactor

* fix: hide commodity variant from selector until testing complete

Only show the commodity option in the variant switcher when the user
is already on the commodity variant (same pattern as happy variant).
Other variants (full, tech, finance) won't see the commodity link.

---------

Co-authored-by: jroachell <jianyin.roachell@siriusxm.com>
Co-authored-by: Elie Habib <elie.habib@gmail.com>

shared/rss-allowed-domains.json

@@ -276,5 +276,18 @@
   "onemileatatime.com",
   "viewfromthewing.com",
   "www.aviationpros.com",
-  "www.aviationweek.com"
+  "www.aviationweek.com",
+  "www.kitco.com",
+  "www.mining.com",
+  "www.commoditytrademantra.com",
+  "oilprice.com",
+  "www.rigzone.com",
+  "www.eia.gov",
+  "www.mining-journal.com",
+  "www.northernminer.com",
+  "www.miningweekly.com",
+  "www.mining-technology.com",
+  "www.australianmining.com.au",
+  "news.goldseek.com",
+  "news.silverseek.com"
 ]