test(client): unit-test the pure-logic modules + wire coverage into CI/Sonar

Stand up a client test suite on Node's built-in runner (no vitest/jsdom — the
targeted modules are plain ESM with no browser/DOM deps) and cover the
meaningful client logic, not presentational components:

- api/client.js: the fetch wrapper — always sends the session cookie, maps a
  non-2xx response to a thrown ApiError (body.message → statusText fallback),
  resolves an empty body to null, sets Content-Type for JSON but NOT for raw
  FormData uploads, and builds/encodes query strings + path params.
- lib/shardEvents.js: describe() across event kinds (payload vs live frame,
  actor name→acct→"Someone" fallback, sale pluralization, champ.update
  branches) and the categoryOf table-consistency check.
- data/regionBuckets.js: the presence roll-up, incl. the first-match-wins
  ordering and the "buckets always reconcile to the total" invariant.
- lib/heroLayout.js: parseLayout's version/shape guard and heroBackground's
  default-vs-custom branch.
- lib/format.js: the date/label formatters + relative-time buckets.

Wiring so these actually count:
- client/package.json gains a `test` script (node --test);
- pr-checks.yml runs the client tests as a PR gate;
- sonarqube.yml generates a client LCOV report and sonar-project.properties
  feeds it alongside the server report (SF paths resolve to client/src/...).

43 client tests; coverage on the tested modules: format/regionBuckets/
heroLayout 100%, api client 86%, shardEvents 80%.

Co-Authored-By: Claude <noreply@anthropic.com>

client/test/regionBuckets.test.js

@@ -0,0 +1,60 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { bucketize, BUCKETS } from '../src/data/regionBuckets.js'
+
+// Unit-test the presence.online region roll-up for the "Players Online" widget.
+// The load-bearing invariant: the bucket counts ALWAYS reconcile to the true
+// total — anything unmatched lands in Wilderness — so the widget can never show
+// a sum that disagrees with the headline online count.
+
+test('bucketize groups named regions into their buckets', () => {
+  const { rows, total } = bucketize({
+    'Britain': 4,
+    'Moonglow': 2,
+    'Despise': 3,
+    'Green Acres House 12': 1, // not a town/dungeon name → Housing
+  })
+  const byId = Object.fromEntries(rows.map((r) => [r.id, r.count]))
+  assert.equal(byId.britain, 4)
+  assert.equal(byId.towns, 2)
+  assert.equal(byId.dungeons, 3)
+  assert.equal(byId.housing, 1)
+  assert.equal(total, 10)
+})
+
+test('first match wins by BUCKETS order: a town-named house region counts as Towns, not Housing', () => {
+  // The towns regex is ^-anchored and towns is checked BEFORE housing, so a house
+  // region whose name starts with a town name is bucketed as Towns. Pinning this
+  // documents the ordering dependency for anyone retuning BUCKETS.
+  const { rows } = bucketize({ 'Trinsic House 12': 1 })
+  const byId = Object.fromEntries(rows.map((r) => [r.id, r.count]))
+  assert.equal(byId.towns, 1)
+  assert.equal(byId.housing, undefined) // empty bucket dropped
+})
+
+test('an unmatched region falls through to Wilderness so counts always reconcile', () => {
+  const { rows, total } = bucketize({ 'Some Unnamed Field': 5, 'Wilderness': 2 })
+  const wilderness = rows.find((r) => r.id === 'wilderness')
+  assert.equal(wilderness.count, 7)
+  assert.equal(total, 7)
+  // The reconciliation guarantee: the buckets sum to the total, exactly.
+  assert.equal(rows.reduce((s, r) => s + r.count, 0), total)
+})
+
+test('bucketize returns rows in BUCKETS order and drops empty buckets', () => {
+  const { rows } = bucketize({ 'Despise': 1, 'Britain': 1 })
+  assert.deepEqual(rows.map((r) => r.id), ['britain', 'dungeons']) // BUCKETS order, no empty towns/housing/wilderness
+})
+
+test('bucketize coerces non-numeric counts and tolerates empty/nullish input', () => {
+  assert.deepEqual(bucketize({}), { rows: [], total: 0 })
+  assert.deepEqual(bucketize(), { rows: [], total: 0 })
+  const { total } = bucketize({ 'Britain': '3', 'Minoc': 'oops' })
+  assert.equal(total, 3) // '3' → 3, 'oops' → 0
+})
+
+test('the last bucket is the catch-all (its match accepts anything)', () => {
+  const last = BUCKETS[BUCKETS.length - 1]
+  assert.equal(last.id, 'wilderness')
+  assert.equal(last.match('literally anything'), true)
+})