quality: web debt batch (tests runner, FireContainer, rate-limit, maps, i18n)

Independent-of-prod quality debt from PENDIENTE.md §2:

- test: migrate broken Jest -> meteortesting:mocha. Tests rewritten to chai +
  Meteor 3 async APIs, moved to test/server/ (server-only). test/server/
  00-setup.test.js re-runs the collection2/accounts init that `meteor test`
  skips (no server/main.js). New comments method + mediaAnalyzers coverage.
  Dropped rest.test.js (removed meteor/http; covered by smoke/). 36 passing.
- fix: scope FireContainer read by the URL _id on the archive route instead of
  a selector-less FiresCollection.findOne() (imports/ui/pages/Fires/Fires.js).
- feat: rate-limit abusable publications via rateLimitSubscriptions (fireFrom*
  and comments.forReference 5/1000ms; geo subs 10/1000ms).
- perf: append loading=async to the Google Maps loader URL (Gkeys.js).
- deps: meteor-accounts-t9n 2.0 -> 2.6 (no gl build -> keep gl->es fallback,
  documented); add 3 missing gl/common.json keys (0 missing now).
- deps: drop jest/babel/enzyme, add chai.

imports/startup/common/i18n.js

@@ -3,7 +3,9 @@ import moment from 'moment';
 // Load the js langs
 import es from 'meteor-accounts-t9n/build/es';
 import en from 'meteor-accounts-t9n/build/en';
-// TODO ask for translation of this
+// meteor-accounts-t9n (2.6.0) ships no Galician build (build/gl.js), so account
+// error messages fall back to Spanish for gl — see setT9() in client/i18n.js.
+// Re-enable this import if the upstream package ever adds a gl translation.
 // import gl from 'meteor-accounts-t9n/build/gl';
 
 const backOpts = {