feat: add continuous multi-touch and long-press drag gestures

[yuan0818]

Summary

This PR extends Artemis' existing Android input path with continuous multi-touch
and long-press drag gestures that cannot be represented reliably by a normal
swipe. perform_gesture is added alongside the existing input primitives and
uses the existing Operator, Validator, MCP, controller, and driver path.

• Support simultaneous pointers and continuous hold/move phases without lifting
  contacts between phases.
• Provide a generic long_press_drag mode with explicit start and end points,
  an initial hold, and an optional delay before release at the endpoint.
• Support cubic Bezier paths with caller-selected endpoints anywhere on screen.
  Edge dwell uses the same drag mode with an endpoint chosen near an edge.
• Update the bundled helper to v1.3.3 with matching capability negotiation and
  APK metadata.

Existing click, swipe, text input, transcript/history representation, and action
execution semantics remain unchanged. Results use the existing ActionResult;
this change introduces no global execution receipt or gesture agent.

Compatibility and execution

Helpers that do not advertise the required gesture capabilities return
UNSUPPORTED. Continuous phases and long-press drag require Android API 26+.
Multi-touch and continuous input are never emulated as sequential swipes.

perform_gesture is not automatically retried after transport timeout because
Android may already have dispatched the input. This rule is scoped to the new
action; existing action retry behavior is unchanged.

Cancellation releases contacts after the current bounded phase and prevents
subsequent phases from starting. Helper-side busy/release protection applies to
helper gesture injection; it does not arbitrate raw ADB input.

Validation

• Python gesture contract, compatibility, and existing action regression tests.
• Android JVM/Robolectric gesture construction, continuation, cancellation,
  release, and busy-state tests.
• Formatting, lint, and type checks passed locally.
• Local Python suite: 2,556 passed, 80 failed, 7 skipped, 8 deselected. All 80
  failing cases also failed against baseline 351ca84 production code in the
  same local environment. The local suite is not fully green.

Real-device validation on A065 / Android 16 (1080 x 2412), using an installed APK
whose SHA-256 matches the bundled artifact:

Scenario	Result
Two-finger pinch	Pass
Two-finger zoom	Pass
Three-finger swipe	Pass
Explicit continuous hold and drag	Pass
Generic long-press drag	Pass
Bezier drag to an interior endpoint	Pass
Caller-selected edge endpoint with delayed release	Pass
Cancellation during a hold	Pass
Ordinary click after cancellation	Pass

The native test app recorded actual Android MotionEvents. The Bezier test ended
at normalized [650, 550] with 0.35 px release-position error and a measured
505 ms stationary interval before release for a requested 500 ms delay. The
edge test measured 1,006 ms for a requested 1,000 ms delay. Cancellation requested
about 500 ms into a 1,800 ms hold released at 1,804 ms without starting movement.
These checks cover live input integration; they do not cover LLM task planning.

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