feat: Wildlife Sightings layer from iNaturalist and Acartia

Recent community wildlife observations, as a new Wildlife group in the
layer panel.

- Server: keyless iNaturalist proxy (v2 observations with only the
  projected fields; undocumented v1 UTFGrid density tiles, decoded on the
  server) sharing one paced queue (burst 4, ~1/s, 60/min, 8,000/day budget,
  up to four in flight), in-memory caches and upstream-only cooldowns;
  Acartia Salish Sea marine-mammal feed rounded to 0.01 degrees with
  comments dropped.
- Layer: grid counts drawn as a soft view-ranked density glow; real sampled
  sightings as taxon badges at their true positions with ambient photo
  thumbnails and labels; obscured records stay privacy cells; a clicked
  sighting stays pinned through camera moves and refreshes.
- Anchored photo card per selection with the single iNaturalist link;
  attribution in the layer row and the Data attribution popover.
- Filters (CONFIRMED, taxa presets) round-trip in share links with token 9.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

server/providers/inaturalist/queue.js

@@ -0,0 +1,109 @@
+import { setTimeout as delay } from 'node:timers/promises';
+
+// A four-request burst keeps a cold view responsive; thereafter every provider
+// call shares the same one-per-second token supply. The rolling minute ceiling
+// queues the few requests a token bucket alone could allow above 60/min.
+const INAT_INTERVAL_MS = 1000;
+const INAT_BURST = 4;
+const INAT_WINDOW_MS = 60_000;
+const INAT_MAX_PER_WINDOW = 60;
+const INAT_MAX_IN_FLIGHT = 4;
+
+/** Observation queries outrank tiles waiting for a token. Aborted consumers
+ * leave the queue before an attempt or daily-budget reservation is spent. */
+export function createInatQueue({
+  now = () => performance.now(),
+  wait = (ms) => delay(ms),
+  intervalMs = INAT_INTERVAL_MS,
+  burst = INAT_BURST,
+  windowMs = INAT_WINDOW_MS,
+  maxInFlight = INAT_MAX_IN_FLIGHT,
+} = {}) {
+  const pending = [];
+  const dispatchedAt = [];
+  let tokens = burst;
+  let refilledAt = null;
+  let running = false;
+  let inFlight = 0;
+  let slotFreed = null;
+
+  function refill() {
+    const at = now();
+    if (refilledAt !== null && intervalMs > 0)
+      tokens = Math.min(
+        burst,
+        tokens + Math.max(0, at - refilledAt) / intervalMs,
+      );
+    if (intervalMs <= 0) tokens = burst;
+    refilledAt = at;
+  }
+
+  function schedule() {
+    if (running) return;
+    running = true;
+    // A microtask also lets same-turn observation queries take priority.
+    void Promise.resolve().then(drain);
+  }
+
+  async function drain() {
+    try {
+      while (pending.length) {
+        if (inFlight >= maxInFlight) {
+          await new Promise((resolve) => (slotFreed = resolve));
+          continue;
+        }
+        refill();
+        const at = now();
+        while (dispatchedAt.length && dispatchedAt[0] <= at - windowMs)
+          dispatchedAt.shift();
+        const tokenWait = tokens < 1 ? (1 - tokens) * intervalMs : 0;
+        const windowWait =
+          windowMs > 0 && dispatchedAt.length >= INAT_MAX_PER_WINDOW
+            ? dispatchedAt[0] + windowMs - at
+            : 0;
+        if (tokenWait > 0 || windowWait > 0) {
+          await wait(Math.ceil(Math.max(tokenWait, windowWait)));
+          continue;
+        }
+        // Stable sorting preserves FIFO order within each priority.
+        pending.sort((a, b) => a.priority - b.priority);
+        const job = pending.shift();
+        job.signal?.removeEventListener('abort', job.abort);
+        if (job.signal?.aborted) {
+          job.reject(job.signal.reason);
+          continue;
+        }
+        tokens -= 1;
+        if (windowMs > 0) dispatchedAt.push(at);
+        inFlight += 1;
+        // A rejected task releases its slot without stopping the queue.
+        void new Promise((resolve) => resolve(job.task()))
+          .then(job.resolve, job.reject)
+          .finally(() => {
+            inFlight -= 1;
+            const wake = slotFreed;
+            slotFreed = null;
+            wake?.();
+          });
+      }
+    } finally {
+      running = false;
+    }
+  }
+
+  return function enqueue(task, { signal, priority = 1 } = {}) {
+    if (signal?.aborted) return Promise.reject(signal.reason);
+    return new Promise((resolve, reject) => {
+      const job = { task, signal, priority, resolve, reject };
+      job.abort = () => {
+        const index = pending.indexOf(job);
+        if (index >= 0) pending.splice(index, 1);
+        signal.removeEventListener('abort', job.abort);
+        reject(signal.reason);
+      };
+      signal?.addEventListener('abort', job.abort, { once: true });
+      pending.push(job);
+      schedule();
+    });
+  };
+}