escala 2+3: Meteor 1.8.3 -> 2.3 (Mongo 3.2 compatible), dead-package remediation

Reaches Meteor 2.3 building + running against Mongo 3.2, REST smoke test
byte-identical to the 1.6.1.1 baseline (all 12 Flutter endpoints green).

Dead/abandoned Atmosphere packages removed or replaced (the upgrade blockers):
- arkham:comments-ui (no Meteor 2.x build; pinned accounts-password@1.x):
  reimplemented the fire-page comments as a React feature:
    imports/api/Comments/ (collection, server methods, publication, media
    analyzers, new-fire-comment email) + imports/ui/components/Comments/CommentsBox.
    Comment text now rendered as safe plain text + image/youtube embed (was
    markdown-to-HTML). Wired into Fires.js; sitemaps.js + migration v11 updated
    to the new collection. Old Blaze/startup comments files deleted.
- nimble:restivus (REST API; pinned accounts-password@1.3.3, CoffeeScript source
  that crashes this build host): vendored as a local package
  packages/nimble-restivus with the .coffee precompiled to plain JS and the
  accounts-password constraint loosened to 2.x. REST behavior unchanged
  (verified by smoke test). This also dropped the entire iron:router stack.
- maximum:server-transform (+ peerlibrary:*, meteorhacks:zones/inject-initial):
  unused; removal broke Meteor.publishTransformed in FalsePositives publications
  -> replaced with plain Meteor.publish (no transform was configured).
- less, markdown (no source files), and the dead test stack
  (meteortesting:mocha, practicalmeteor:chai, xolvio:cleaner) which transitively
  pulled coffeescript@1.0.17 — the build plugin that crashed meteor-tool
  (node_contextify assertion) on this machine. Removing it unblocked the build.
- fourseven:scss 4.5.4 -> 4.14.1 (node-sass 4.5.3 doesn't build on node 12).

npm-mongo driver at 2.3 is 3.9.x — still compatible with the production Mongo
3.2 replica set.

imports/api/Comments/server/publications.js

@@ -0,0 +1,14 @@
+/* eslint-disable import/no-absolute-path */
+/* eslint-disable prefer-arrow-callback */
+import { Meteor } from 'meteor/meteor';
+import { check } from 'meteor/check';
+import Comments from '/imports/api/Comments/Comments';
+
+// Comments for one reference (a fire page), oldest first.
+Meteor.publish('comments.forReference', function commentsForReference(referenceId) {
+  check(referenceId, String);
+  return Comments.find(
+    { referenceId },
+    { sort: { createdAt: 1 } }
+  );
+});