feat(frontend): rocket-launch animation on Run button click

[chenlica]

What changes were proposed in this PR?

Adds a small fun visual flourish to the workflow editor: when the user clicks
the Run button in the top toolbar, a 🚀 emoji is spawned at the button's
position, traces three counterclockwise loops to the left of the button, and
then accelerates straight up off the top of the viewport.

Details:

• Animation logic is extracted into a pure utility module,
  frontend/src/app/workspace/component/menu/launch-rocket.ts, so it can be
  unit-tested without bootstrapping the heavyweight MenuComponent TestBed
  (the existing menu.component.spec.ts is entirely commented out and has no
  working setup).
• MenuComponent.onRunButtonClick() invokes launchRocket(...) and then
  delegates to the existing dynamic onClickRunHandler so all existing button
  states (Run / Pause / Resume / Connect / Submitting / …) continue to work.
• The animation uses the Web Animations API — no new CSS, no new dependencies.

Any related issues, documentation, discussions?

None. Cosmetic-only change isolated to the workflow editor's top menu.

How was this PR tested?

A new Jasmine spec covers the utility:
frontend/src/app/workspace/component/menu/launch-rocket.spec.ts — 13 tests,
all passing under yarn ng test --include="**/launch-rocket.spec.ts".

The tests verify:

• returns null and creates no DOM when given null
• appends a 🚀 element to document.body, positioned at the button's center
• calls Element.prototype.animate with the configured duration
• emits cycles × steps + 1 orbit keyframes plus the shoot-up keyframe
• the orbit forms a closed counterclockwise loop (starts and ends at translate(0px, 0px))
• rotation is strictly monotonically decreasing across orbit keyframes, with total angular distance equal to 360° × cycles (proves CCW + cycle count)
• every orbit dx is non-positive (the circle is to the left of the start)
• the shoot-up keyframe has opacity: 0, translates upward, and uses a rotation congruent to "pointing up" modulo 360°
• the rocket element is removed when Animation.onfinish fires
• multiple clicks create independent rockets
• the orbit radius auto-shrinks when the Run button is close to the left edge of the viewport (≥ 40px, < 140px)

Also manually verified in ng serve by clicking the Run button on a runnable workflow.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Claude Code (Claude Sonnet 4.6, 1M context, Anthropic, 2026-05-14)

[chenlica]

it's a prototype to learn how to use Claude to raise a PR