feat(voice): add reusable geometry actions

- turn named places and mapped landmarks into reusable bounded areas
- count loaded records inside resolved, drawn and annotated geometry
- find recent imagery for an area, the view or the pointer snapshot
- keep osm place search behind an operator-configured overpass endpoint
- preserve cancellation, ownership and follow-up memory across every action
- cover geometry, provider lifecycle, cache isolation and voice routing

server/providers/overpass/osmFeatures.js

@@ -0,0 +1,191 @@
+import { OSM_PRESETS } from '../../../src/data/osmPresets.js';
+
+/**
+ * Bounded, typed OpenStreetMap feature search: one preset from the curated
+ * table inside a bounding box.
+ *
+ * The request carries a preset id, a box, a mode and a limit — never query
+ * text. The server writes the Overpass query itself and bounds it: box size
+ * per mode (a count may cover more ground than a fetch), result count,
+ * Overpass timeout and memory, response bytes, and one query in flight. It
+ * runs only against the operator's `OVERPASS_UPSTREAMS`; the generic
+ * `/api/overpass` guard is untouched.
+ *
+ * There is deliberately no boundary (`area`) filter: Overpass servers differ
+ * in whether they hold area data, and one without it answers zero rather than
+ * failing. The browser filters the box's features by the exact area geometry
+ * instead, so a count inside a province is exact and a box count is labelled
+ * as a box count.
+ */
+export const OSM_FEATURE_LIMITS = Object.freeze({
+  /** Largest box a fetch may cover, in square degrees (~200 × 200 km at the equator). */
+  maxFetchDeg2: 4,
+  /** Largest box a count may cover. */
+  maxCountDeg2: 36,
+  /** Most features one fetch returns. */
+  maxLimit: 1000,
+  /** Overpass server-side timeout, seconds. */
+  timeoutS: 25,
+  /** Overpass server-side memory cap, bytes. */
+  maxsize: 64 * 1024 * 1024,
+  /** Response bytes read from the upstream. */
+  maxResponseBytes: 16 * 1024 * 1024,
+  /** Per-upstream wait: a busy Overpass answers these in 10–30 s. */
+  upstreamTimeoutMs: 40_000,
+});
+
+/** Tags a returned feature keeps, besides the preset's own. */
+const KEPT_TAGS = [
+  'name',
+  'name:en',
+  'operator',
+  'brand',
+  'opening_hours',
+  'wheelchair',
+  'emergency',
+  'healthcare',
+  'addr:street',
+  'addr:city',
+];
+
+const quote = (text) =>
+  `"${String(text).replace(/\\/g, '\\\\').replace(/"/g, '\\"')}"`;
+
+/**
+ * Parse and bound a request. Returns the compiled query or a refusal.
+ * @param {{preset: string, bbox: string|number[], mode?: string, limit?: string|number}} request
+ * @returns {{ok: true, ql: string, mode: string, preset: object, limit: number, boxes: number[][]}|{ok: false, code: string, error: string}}
+ */
+export function compileOsmFeatureQuery(request = {}) {
+  const refuse = (code, error) => ({ ok: false, code, error });
+  const presetId = String(request.preset || '');
+  const preset = Object.hasOwn(OSM_PRESETS, presetId)
+    ? OSM_PRESETS[presetId]
+    : null;
+  if (!preset) return refuse('UNKNOWN_PRESET', 'Unknown feature kind.');
+  const mode = request.mode === 'count' ? 'count' : 'features';
+  const parts = (
+    Array.isArray(request.bbox)
+      ? request.bbox
+      : String(request.bbox || '').split(',')
+  ).map(Number);
+  if (parts.length !== 4 || !parts.every(Number.isFinite))
+    return refuse('BAD_BOX', 'bbox needs west,south,east,north.');
+  const [west, south, east, north] = parts;
+  if (
+    Math.abs(west) > 180 ||
+    Math.abs(east) > 180 ||
+    south < -90 ||
+    north > 90 ||
+    south >= north ||
+    west === east
+  )
+    return refuse('BAD_BOX', 'bbox edges are out of range.');
+  // A box crossing the antimeridian is searched as its two halves.
+  const boxes =
+    west < east
+      ? [[south, west, north, east]]
+      : [
+          [south, west, north, 180],
+          [south, -180, north, east],
+        ];
+  const deg2 = boxes.reduce((sum, [s, w, n, e]) => sum + (n - s) * (e - w), 0);
+  const cap =
+    mode === 'count'
+      ? OSM_FEATURE_LIMITS.maxCountDeg2
+      : OSM_FEATURE_LIMITS.maxFetchDeg2;
+  if (deg2 > cap)
+    return refuse(
+      'AREA_TOO_LARGE',
+      mode === 'count'
+        ? 'That area is too large to search; narrow it down.'
+        : 'That area is too large to list; count first or narrow it down.',
+    );
+  const requested = Number(request.limit);
+  const limit = Math.max(
+    1,
+    Math.min(
+      OSM_FEATURE_LIMITS.maxLimit,
+      Number.isFinite(requested) ? Math.trunc(requested) : 500,
+    ),
+  );
+  const selectors = [];
+  for (const [key, value] of preset.tags)
+    for (const [s, w, n, e] of boxes)
+      selectors.push(
+        `nwr[${quote(key)}=${quote(value)}](${s},${w},${n},${e});`,
+      );
+  const ql =
+    `[out:json][timeout:${OSM_FEATURE_LIMITS.timeoutS}][maxsize:${OSM_FEATURE_LIMITS.maxsize}];` +
+    `(${selectors.join('')});` +
+    (mode === 'count' ? 'out count;' : `out center tags ${limit};`);
+  return { ok: true, ql, mode, preset, limit, boxes };
+}
+
+/**
+ * Overpass JSON → the compact answer the browser gets.
+ * @param {object} payload Parsed Overpass JSON.
+ * @param {{mode: string, preset: object, limit: number}} compiled
+ */
+export function summarizeOsmFeatures(payload, compiled) {
+  if (!Array.isArray(payload?.elements))
+    throw new TypeError('Malformed Overpass feature response');
+  const elements = payload.elements;
+  if (compiled.mode === 'count') {
+    const tags = elements.find((el) => el?.type === 'count')?.tags;
+    const rawTotal = tags?.total;
+    const total = Number(rawTotal);
+    if (
+      !tags ||
+      !Object.hasOwn(tags, 'total') ||
+      !['string', 'number'].includes(typeof rawTotal) ||
+      String(rawTotal).trim() === '' ||
+      !Number.isSafeInteger(total) ||
+      total < 0
+    )
+      throw new TypeError('Malformed Overpass count response');
+    return {
+      mode: 'count',
+      preset: compiled.preset.id,
+      count: total,
+      nodes: Number(tags.nodes) || 0,
+      ways: Number(tags.ways) || 0,
+      relations: Number(tags.relations) || 0,
+    };
+  }
+  const features = [];
+  let unplaced = 0;
+  for (const el of elements) {
+    if (
+      !['node', 'way', 'relation'].includes(el?.type) ||
+      (!Number.isFinite(Number(el?.id)) && typeof el?.id !== 'string')
+    ) {
+      unplaced += 1;
+      continue;
+    }
+    const lat = Number.isFinite(el?.lat) ? el.lat : el?.center?.lat;
+    const lon = Number.isFinite(el?.lon) ? el.lon : el?.center?.lon;
+    if (!Number.isFinite(lat) || !Number.isFinite(lon)) {
+      unplaced += 1;
+      continue;
+    }
+    const tags = {};
+    for (const key of [...KEPT_TAGS, ...compiled.preset.tags.map(([k]) => k)])
+      if (typeof el.tags?.[key] === 'string')
+        tags[key] = el.tags[key].slice(0, 120);
+    features.push({ id: `${el.type}/${el.id}`, lat, lon, tags });
+  }
+  // A genuinely empty `elements` array is authoritative. A non-empty answer
+  // whose every row is unusable is a schema failure, not "zero places"; do
+  // not let the route cache that as current state for a day.
+  if (elements.length && features.length === 0)
+    throw new TypeError('Overpass feature response has no usable rows');
+  return {
+    mode: 'features',
+    preset: compiled.preset.id,
+    count: features.length,
+    features,
+    truncated: elements.length >= compiled.limit,
+    ...(unplaced ? { unplaced } : {}),
+  };
+}