Add and export resetCLS to reset CLS metric

[srubin]

Mirrors the resetINP change (#1, #2) for CLS: dispatching a reset-web-vitals-cls event re-initializes the CLS metric and its session-window state while keeping existing callbacks, so consumers can report CLS in fixed intervals (Descript reports the worst session burst per 5-minute window, like INP).

Exported from both the standard and attribution builds, and bumps the version to 3.5.2-descript.3.

Includes an e2e test mirroring 'resets INP metric'; I authored it to match the existing suite but have not run the test suite locally. After merge this needs an npm publish of 3.5.2-descript.3 so the monorepo can pick it up (BIX-8613).

🤖 Generated with Claude Code

[srubin]

Apologies — opened against upstream by mistake; this is intended for Descript's fork.

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[tunetheweb]

Interesting! Have you considered the soft nav support added in v6?

Though that would be Chromium-only whereas INP is available in Safari and Firefox so the manual reset would alow them to be supported for INP (they don't support CLS).

[srubin]

Oh, TIL. But no, I don't think soft navs are sufficient for our use case, because the URL isn't changing. In our case, we are tracking these metrics for each 5 minute segment of an hours-long audio/video editing session.

[tunetheweb]

Oh gotcha. Yeah that is a different use case.