#42977 test: remove jest snapshot tests

Proposed changes

Removes the Jest snapshot tests. Most specs rendered every story and called toMatchSnapshot() on the whole DOM. That produced ~90k lines of .snap files that break on any markup change and don't assert any specific behavior.

• 138 tests whose only assertion was a snapshot are removed. The a11y tests that render the same stories are kept.
• 2 stray toMatchSnapshot() lines were removed from tests that have other assertions (ThreadMessagePreviewBody, SettingToggle).
• All 137 .snap files are deleted.
• 3 specs that had nothing left (RoomFormAttributeField, BannedUsers, HeaderTag) are deleted.
• In the e2ee specs (binary.spec.ts, content.spec.ts), inline value snapshots are now explicit toBe/toThrow assertions, so no coverage is lost.
• Leftovers are cleaned up: empty describe blocks, a fake-timer setup that only existed for the snapshots, unused variables, and comments whose rationale was the snapshot.

Playwright visual-regression snapshots are untouched.

Issue(s)

https://rocketchat.atlassian.net/browse/ARCH-2574

Steps to test or reproduce

git grep -E 'toMatchSnapshot|toMatchInlineSnapshot|ErrorMatching(Inline)?Snapshot' returns nothing. Unit test CI should pass with Snapshots: 0 total.

Further comments

This is a test-only change, so there's no changeset.

Summary by CodeRabbit

• Tests
  • Removed broad Storybook snapshot and render-smoke tests across application and UI components.
  • Retained accessibility, interaction, validation, focus, and behavior-focused coverage.
  • Replaced inline snapshot assertions in encryption-related tests with direct value and error-message checks.
  • Updated asynchronous accessibility verification to wait for dynamically rendered content where needed.
  • Simplified test maintenance while preserving checks for key user-facing behavior and accessibility.