refactor(live-atc): extract bridge-telemetry normalization to shared/utils, add tests

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/shared/bridgeTelemetry.test.ts

@@ -0,0 +1,51 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import {
+  normalizeSimFreq,
+  normalizeBridgeTelemetry,
+  telemetrySignature,
+} from '../../shared/utils/bridgeTelemetry.ts'
+
+test('normalizeSimFreq formats a valid COM value to 3 decimals', () => {
+  assert.equal(normalizeSimFreq(119.9), '119.900')
+})
+
+test('normalizeSimFreq rejects out-of-band values', () => {
+  assert.equal(normalizeSimFreq(50), null)
+  assert.equal(normalizeSimFreq('not-a-number'), null)
+})
+
+test('normalizeBridgeTelemetry maps SimConnect field names', () => {
+  const result = normalizeBridgeTelemetry({
+    PLANE_ALTITUDE: 3500,
+    AIRSPEED_INDICATED: 140,
+    GROUND_VELOCITY: 138,
+    VERTICAL_SPEED: 800,
+    PLANE_HEADING_DEGREES_TRUE: 270,
+    SIM_ON_GROUND: false,
+  })
+  assert.deepEqual(result, {
+    altitude_ft: 3500,
+    ias_kts: 140,
+    gs_kts: 138,
+    vs_fpm: 800,
+    heading_deg: 270,
+    on_ground: false,
+  })
+})
+
+test('normalizeBridgeTelemetry returns null for non-object input', () => {
+  assert.equal(normalizeBridgeTelemetry(null), null)
+})
+
+test('telemetrySignature is stable under sub-threshold jitter', () => {
+  const a = telemetrySignature({ altitude_ft: 3500, ias_kts: 140, on_ground: false })
+  const b = telemetrySignature({ altitude_ft: 3540, ias_kts: 141, on_ground: false })
+  assert.equal(a, b)
+})
+
+test('telemetrySignature changes on a meaningful altitude change', () => {
+  const a = telemetrySignature({ altitude_ft: 3500, on_ground: false })
+  const b = telemetrySignature({ altitude_ft: 4200, on_ground: false })
+  assert.notEqual(a, b)
+})