Make gestures cooperate with scrolling and feel smoother

From an app built on core-v2:

Scrolling (#3, #4, #14)
- Each recognizer locks onto a touch within its first 6px: along its axis
  and direction it holds the touch, otherwise it lets go. A new
  onTouchmove binding cancels native scrolling only while a recognizer
  holds the touch, so hosts use touch-action: manipulation and one
  vertical gesture no longer disables vertical scrolling. Several
  gestures on one host share touches through the same rule.
- .from.scrollEdge(scroller, edge) admits drag-to-dismiss only while a
  scroller is at the edge (#5).

Feel
- recognition.distance sets what counts as full progress: pixels, a CSS
  length, or a measuring function (#6).
- Choreographies receive overshoot, the drag past either end of the
  clamped progress, and the settling spring starts from it (#7).
- Velocity is the least-squares trend of the last 100ms (#8).
- Defaults retuned to commitThreshold 0.25 and commitVelocity 0.2; the
  slide presets use them (#9).
- Choreographies may set spring stiffness and damping (#10).

Hooks and helpers
- .onArm()/.onDisarm() run during a drag when releasing would start or
  stop committing (#12).
- startedIn, nearEdge, atScrollEdge, anyOf, allOf start predicates (#15).
- Development builds warn when an operation's first frame moves a node
  that was visibly at rest, the one-frame "pop" of mismatched open and
  close choreographies (#16).

Docs: scrolling, ignored elements, animation performance, haptics, and
operating-system edge gestures including CloseWatcher/popstate for PWAs
(#11, #17, #18).

Verification: a Chromium harness with emulated touch (verify/browser)
checks swipes over scrollers, native scrolling beside gestures,
scroll-edge dismissal, onCommit inside pointerup, and the continuity
warning. Reverting the earlier capture fix makes it fail exactly as
reported ("none of the handles work").

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

packages/core-v2/src/scene/graph.ts

@@ -65,13 +65,13 @@ export class OriginSceneError extends Error {
  * Progress at which a release commits when the choreography does not supply
  * its own `commitThreshold`.
  */
-export const DEFAULT_COMMIT_THRESHOLD = 0.36;
+export const DEFAULT_COMMIT_THRESHOLD = 0.25;
 
 /**
  * Release velocity (progress units per second) that commits a flick at any
  * progress when the choreography does not supply its own `commitVelocity`.
  */
-export const DEFAULT_COMMIT_VELOCITY = 0.3;
+export const DEFAULT_COMMIT_VELOCITY = 0.2;
 
 /**
  * Decide a release outcome from explicit options, or from velocity and
@@ -274,6 +274,7 @@ export class SceneGraph {
     const operation = this.operations.get(id);
     if (!operation || operation.phase === "finished") return;
     operation.progress = clamp01(progress);
+    operation.overshoot = progress - operation.progress;
     operation.velocity = velocity;
     if (operation.phase !== "preparing") operation.phase = "interactive";
   }
@@ -297,6 +298,7 @@ export class SceneGraph {
 
     if (operation.history === "push" && operation.choreography.persistAtRest) {
       operation.progress = 1;
+      operation.overshoot = 0;
       operation.velocity = 0;
       operation.intent = "commit";
       operation.phase = "finished";
@@ -545,6 +547,7 @@ export class SceneGraph {
       placement: init.placement,
       history: init.history,
       progress: 0,
+      overshoot: 0,
       velocity: 0,
       phase: "preparing",
       intent: "undecided",