feat: finish Stage 2B continuous sorter realism and local deploy

Unify CAD conveyor on / and /details, add RealSense D435i + contact paddle
physics, keep items moving through scan, lock 7×10 drop validation, and
ship Stage 2 artifacts with production on :3100 (permanent HTTPS still blocked).

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/drop-validation.mts

@@ -0,0 +1,92 @@
+/**
+ * Stage 2B §16 — mandatory drop validation: 7 routes × 10 runs (headless Rapier).
+ *
+ * Uses the SAME simulateDrop as the unit tests — same colliders, profiles,
+ * handoff and pusher as the runtime. Writes docs/stage2_real_sorter/drop-validation.json.
+ *
+ * Note: the sim is deterministic (fixed dt, no RNG), so the 10 runs per route
+ * are identical repetitions validating stability, not a Monte Carlo sample.
+ * Runtime variability is covered by the browser e2e (variable frame rate).
+ */
+import { writeFileSync, mkdirSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { initRapier, simulateDrop } from '../src/domain/physicsDropSim';
+
+const here = dirname(fileURLToPath(import.meta.url));
+const OUT = join(here, '../docs/stage2_real_sorter/drop-validation.json');
+
+const RUNS = 10;
+const ROUTES: { sku: string; zone: 'B' | 'C' | 'D'; label: string }[] = [
+  { sku: 'SKU-001', zone: 'B', label: 'box → B' },
+  { sku: 'SKU-009', zone: 'C', label: 'pen → C' },
+  { sku: 'SKU-005', zone: 'C', label: 'pouf → C' },
+  { sku: 'SKU-004', zone: 'C', label: 'oversized → C' },
+  { sku: 'SKU-007', zone: 'D', label: 'bottle → D' },
+  { sku: 'SKU-006', zone: 'D', label: 'plate → D' },
+  { sku: 'SKU-008', zone: 'D', label: 'cylinder → D' },
+];
+
+// Work-area bounds (m) — anything outside is out-of-bounds.
+const BOUNDS = { x: [-2.6, 4.2], y: [-0.05, 2.5], z: [-2.6, 2.6] };
+const SPEED_TELEPORT_CAP = 8; // m/s — above this is a solver blowup/teleport
+const PENETRATION_DEPTH = 0.006; // m below the belt surface = critical penetration
+
+await initRapier();
+
+const report = {
+  generatedAt: new Date().toISOString(),
+  sim: 'headless Rapier via simulateDrop (deterministic, dt=1/60, settle 6s)',
+  runs: RUNS,
+  routes: [] as unknown[],
+  summary: { totalRoutes: 0, passedRoutes: 0, result: 'PASS' as 'PASS' | 'FAIL' },
+};
+
+for (const route of ROUTES) {
+  let correct = 0;
+  let penetrations = 0;
+  let teleports = 0;
+  let outOfBounds = 0;
+  let frozenInAir = 0;
+  let pusherContacts = 0;
+  const finals: string[] = [];
+  for (let run = 0; run < RUNS; run += 1) {
+    const r = simulateDrop(route.sku, route.zone);
+    if (r.insideExpectedReceiver) correct += 1;
+    if (r.minClearanceM < -PENETRATION_DEPTH) penetrations += 1;
+    if (r.maxSpeedMps > SPEED_TELEPORT_CAP) teleports += 1;
+    const [x, y, z] = r.finalPosition;
+    if (x < BOUNDS.x[0] || x > BOUNDS.x[1] || y < BOUNDS.y[0] || y > BOUNDS.y[1] || z < BOUNDS.z[0] || z > BOUNDS.z[1]) {
+      outOfBounds += 1;
+    }
+    // Frozen in air: settled above floor level but NOT inside the receiver.
+    if (!r.insideExpectedReceiver && y > 0.4) frozenInAir += 1;
+    if (r.pusherContactMade) pusherContacts += 1;
+    if (run < 3) finals.push(`(${x.toFixed(2)},${y.toFixed(2)},${z.toFixed(2)})`);
+  }
+  const pass = correct === RUNS && penetrations === 0 && teleports === 0 && outOfBounds === 0 && frozenInAir === 0
+    && (route.zone === 'B' || pusherContacts === RUNS);
+  report.routes.push({
+    sku: route.sku,
+    route: route.label,
+    expectedZone: route.zone,
+    runs: RUNS,
+    correctLandings: correct,
+    penetrations,
+    teleports,
+    outOfBounds,
+    frozenInAir,
+    pusherContacts: route.zone === 'B' ? 'n/a' : pusherContacts,
+    sampleFinalPositions: finals,
+    result: pass ? 'PASS' : 'FAIL',
+  });
+  report.summary.totalRoutes += 1;
+  if (pass) report.summary.passedRoutes += 1;
+  console.log(`${pass ? 'PASS' : 'FAIL'} ${route.label} (${route.sku}): ${correct}/${RUNS} landings, pen=${penetrations}, tp=${teleports}, oob=${outOfBounds}, air=${frozenInAir}, pusher=${route.zone === 'B' ? 'n/a' : pusherContacts}`);
+}
+
+if (report.summary.passedRoutes !== report.summary.totalRoutes) report.summary.result = 'FAIL';
+mkdirSync(dirname(OUT), { recursive: true });
+writeFileSync(OUT, JSON.stringify(report, null, 2));
+console.log(`\n${report.summary.passedRoutes}/${report.summary.totalRoutes} routes PASS -> ${OUT}`);
+process.exit(report.summary.result === 'PASS' ? 0 : 1);