test(voice): pin diagnostics wiring and in-flight crop dedupe; tighten docs

Third review pass on #835. No runtime change.

- Controller test: viewport decisions reach the controller's debug log.
- Policy test: a second request for a snapshot still being captured is
  logged pointer-already-requested and is not captured twice.
- CURRENT-STATE: pointer-not-fresh also covers a missing snapshot,
  already-requested covers an earlier attempt that threw, and the image
  step runs when any tool output of the response was sent.
- Changelog: describe what is recorded rather than a fixed miscount.

src/voice/gevRealtime.test.mjs

@@ -3708,3 +3708,29 @@ test('voice runs app actions itself and other tools through the catalog', async
   assert.deepEqual(disposals, [['removed']]);
   assert.equal(withToolCatalog(runner, undefined), runner);
 });
+
+test('the controller forwards viewport escalation diagnostics to its debug log', async () => {
+  const records = [];
+  const controller = new GevRealtimeController({
+    ui: createTestVoiceUi(),
+    runner: async () => ({ ok: true }),
+    radioLayer: { subscribePlaybackControls: () => () => {}, setVoiceDucked() {} },
+  });
+  controller.debugLog = (event, detail) => records.push({ event, detail });
+  controller.dc = { readyState: 'open', send() {}, close() {} };
+
+  assert.equal(
+    await controller.sendVisualContextIfUseful({
+      action: 'get_entity_context',
+      scene: { basemap: { viewScale: 'regional' } },
+    }),
+    false,
+  );
+  assert.deepEqual(
+    records.filter((record) => record.event.startsWith('viewport_context.')),
+    [{
+      event: 'viewport_context.decision',
+      detail: { contextId: 1, send: false, reason: 'view-scale-not-local', viewScale: 'regional' },
+    }],
+  );
+});

src/voice/realtimeViewportPolicy.test.mjs

@@ -557,3 +557,27 @@ test('a throw after a real send still logs it as sent', async () => {
     [['viewport_context.result', 'sent']],
   );
 });
+
+test('a second request for a snapshot still being captured is not sent twice', async () => {
+  const releases = [];
+  const snapshot = groundSnapshot();
+  const { viewport, events } = recordingViewport({
+    readPointer: () => snapshot,
+    capturePointer: () => new Promise((resolve) => releases.push(resolve)),
+  });
+  const first = viewport.sendVisualContextIfUseful(pointerGround());
+  const second = viewport.sendVisualContextIfUseful(pointerGround());
+  await Promise.resolve();
+  for (const release of releases)
+    release({ dataUrl: 'data:image/jpeg;base64,AA==', rect: {} });
+  assert.deepEqual([await first, await second], [true, false]);
+  assert.equal(releases.length, 1);
+  const outcomes = events.filter((item) => outcomeEvents.has(item.event));
+  assert.deepEqual(
+    outcomes.map((item) => [item.detail.contextId, item.detail.reason]),
+    [
+      [2, 'pointer-already-requested'],
+      [1, 'sent'],
+    ],
+  );
+});