Fix Gnawnian Express Station phase selection

[SoilChang]

Currently broken

get-data.js:93 Error loading data: TypeError: Cannot set properties of null (setting 'selectedIndex')
    at shared-cre-setup.js:1065:55
    at loadDropdown (shared-cre-setup.js:973:3)
    at phaseChanged (shared-cre-setup.js:1064:5)
    at icebergPhase (cre.js:871:7)
    at baseChanged (cre.js:881:3)
    at loadDropdown (shared-cre-setup.js:973:3)
    at allDataLoaded (cre.js:139:3)
    at checkLoadState (shared-cre-setup.js:1558:5)
    at tryCheckLoadState (get-data.js:123:7)
    at setWisdom (get-data.js:136:5)

How the Iceberg logic leads to the stacktrace

1. allDataLoaded() populates the Base dropdown with loadDropdown(), whose callback is baseChanged().
2. baseChanged() calls icebergPhase() for every location; the function originally had no location guard.
3. At Gnawnian Express Station, a valid phase can be Supply Depot (Supply Rush) or Supply Depot (No Supply Rush). icebergPhase() normalizes every phase using phaseName.split(" (")[0], turning the selected phase into Supply Depot.
4. Supply Depot is not a valid Gnawnian Express Station phase option. The select therefore loses its value, and icebergPhase() calls phaseChanged().
5. phaseChanged() converts the empty value to EMPTY_SELECTION (-), finds no popArray[locationName]["-"], and calls loadDropdown() to rebuild the phase list.
6. The recovery callback then executes document.getElementById("#phase").selectedIndex = 0. Because getElementById() expects phase without the #, it returns null, producing the reported selectedIndex exception.

The fix limits icebergPhase() to the Iceberg location and corrects the phase element lookup.

Summary

• Restrict Iceberg phase normalization to the Iceberg location.
• Preserve Gnawnian Express Station phases such as Supply Depot (Supply Rush) when changing bases.
• Fix the invalid getElementById("#phase") lookup used during phase-dropdown recovery.

Testing

• git diff --check
• node --check src/main/cre.js
• node --check src/main/shared-cre-setup.js
• npm run population
• npm run mouse-data
• npm run trap-data
• npm run minify
• Verified the Catch Rate Estimator locally at http://127.0.0.1:8000/cre.html.