Fix touch gestures cancelling, backward flicks, and late onCommit

- Only the host's own lostpointercapture cancels a gesture. Taking
  capture makes the touched child lose its implicit touch capture, and
  that bubbling event was cancelling every touch gesture immediately.
- A flick at least commitVelocity fast now decides by its direction:
  backward cancels even past the distance threshold, forward commits.
  Slower releases still decide by distance.
- Pointer-up finishes an already-begun operation without awaiting, so
  onCommit runs inside the pointer-up event, where iOS still allows
  haptics, audio, and clipboard writes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Faarh2Ts6StJPcz2mRiHiR

packages/core-v2/tests/recognizer.test.ts

@@ -108,6 +108,26 @@ describe("stuck gestures", () => {
     expect(scene.nodes.value).toHaveLength(1);
   });
 
+  it("ignores a child losing implicit touch capture to the host", async () => {
+    const Root = defineComponent({
+      setup: () => () =>
+        h(OriginGesture, { id: "host", gesture: definition }, () =>
+          h("span", { id: "child" }, "x"),
+        ),
+    });
+    const { scene, host } = await mount(Root);
+    await dragLeft(host);
+    expect(scene.operations.value).toHaveLength(1);
+
+    // Taking capture on the host makes the touched child lose its implicit
+    // capture; that event bubbles to the host.
+    host
+      .querySelector("#child")!
+      .dispatchEvent(pointer("lostpointercapture", 120, 110));
+    await flush();
+    expect(scene.operations.value).toHaveLength(1);
+  });
+
   it("ignores lostpointercapture after a normal release", async () => {
     const { scene, host } = await mount(gestureHost(() => definition));
     await dragLeft(host);
@@ -318,6 +338,22 @@ describe("commitVelocity", () => {
     expect(shouldCommit(operation(0.1, 0.15), {})).toBe(true);
   });
 
+  it("lets a fast flick's direction veto the distance", () => {
+    const at = (progress: number, velocity: number) =>
+      ({
+        progress,
+        velocity,
+        choreography: { effects: () => ({}) },
+      }) as unknown as Parameters<typeof shouldCommit>[0];
+    // Past the 0.36 threshold, but flicked back toward the start: cancels.
+    expect(shouldCommit(at(0.8, -0.5), {})).toBe(false);
+    // Barely started, but flicked forward: commits.
+    expect(shouldCommit(at(0.05, 0.5), {})).toBe(true);
+    // Slow releases fall back to distance, in either direction.
+    expect(shouldCommit(at(0.8, -0.1), {})).toBe(true);
+    expect(shouldCommit(at(0.2, 0.1), {})).toBe(false);
+  });
+
   it("still yields to an explicit decision", () => {
     expect(shouldCommit(operation(0.1, 5), { commit: false })).toBe(false);
   });