[Feature] Remove deprecated Publish to Expo Host command

[ConnorQi01]

Summary

The publishToExpHost command invokes the classic expo publish workflow via XDL.publish(). Expo deprecated and sunset classic updates publishing in 2024; the xdl package is archived. This command no longer works in modern Expo projects and is stale dead code in the extension.

Why this is useful

Removing this command eliminates a broken/confusing entry from the command palette for modern Expo users, reduces maintenance surface, and continues the XDL cleanup already started in 1.14.0 ("Remove unused XDL deprecated fields from Expo").

Suggested scope

• Delete src/extension/commands/publishToExpHost.ts
• Remove its export from src/extension/commands/index.ts
• Remove the reactNative.publishToExpHost command registration from package.json and its title entry from package.nls.json
• Remove FailedToPublishToExpHost from src/common/error/internalErrorCode.ts and the matching string from src/common/error/errorStrings.ts
• Update CHANGELOG

Evidence

• src/extension/commands/publishToExpHost.ts calls XDL.publish() — the xdl npm package is archived and no longer maintained
• CHANGELOG 1.14.0 already includes "Remove unused XDL deprecated fields from Expo [Remove unused deprecated XDL fields #2685]" — indicating active XDL cleanup
• expo publish (classic updates) was sunset by Expo; modern projects use EAS Update (eas update)
• The command has no unit test, no smoke test, and no README documentation

Validation

• Confirm Publish To Expo Host no longer appears in the command palette after removal
• npm run build (or gulp build) passes with no TypeScript errors