fix(record): resync replaces grown sheets instead of re-sending the tail

[mayberryzane]

When the insertRule patch has been displaced, the stylesheet resync re-sent only the tail of each grown sheet. That assumes missed rules were appended. styled-components inserts rules mid-sheet (at each component's group offset), so the replayer received shifted duplicates and never got the new rules. The resync now replaces the replayer's copy of any sheet whose rule count changed, the same path it already used for sheets that shrank.

Test: new case in stylesheet-resync.test.ts inserts a rule mid-sheet while the patch is displaced, then applies the recorded events the way the replayer does and checks the result against the live sheet. It fails without the fix (the copy ends with a duplicated last rule and lacks the inserted one) and passes with it. test/record, test/replay and replayer.test.ts pass (239 tests); typecheck passes.

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Note

Overview
Fixes stylesheet resync when the insertRule patch is displaced and the recorder missed CSSOM updates. Previously, a higher live rule count triggered re-sending only the tail of rules, which breaks libraries like styled-components that insert mid-sheet—replays duplicated shifted rules and dropped the new ones.

resyncCssomStyleSheets now fully replaces the replayer’s copy of any sheet whose rule count no longer matches what was reported (same path already used when a sheet shrank), instead of incremental tail adds. The unused styleSheetAddRule import is removed.

A new integration test simulates mid-sheet insertion while the patch is off, replays recorded stylesheet events like the replayer, and asserts the replayed rules match the live sheet.

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