perf(ci): increase E2E sharding from 3 to 10

[CybotTM]

Summary

Increase E2E test sharding from 3 to 10 parallel jobs for faster CI execution.

Test plan

• CI completes with 10 E2E shards running in parallel

[Copilot]

Pull request overview

This PR increases E2E test sharding from 3 to 10 parallel jobs to reduce CI execution time by distributing Playwright tests across more workers.

Changes:

• Updated the GitHub Actions matrix to spawn 10 E2E test jobs instead of 3
• Modified step names and Playwright CLI arguments to reflect the new shard count

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 46.07%. Comparing base (177f389) to head (ca23a13).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #256   +/-   ##
=========================================
  Coverage     46.07%   46.07%           
  Complexity     2627     2627           
=========================================
  Files           172      172           
  Lines          7205     7205           
=========================================
  Hits           3320     3320           
  Misses         3885     3885           

Flag	Coverage Δ
unit	46.07% <ø> (ø)

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