test(web): query plugin item actions by name

[lyzno1]

Summary

• Replace every remaining single-action positional locator in the plugin item action tests with a helper that queries the intended action by role and accessible name.
• Remove the generic getActionButtons helper so future tests cannot silently bind behavior to toolbar order.
• Keep absence checks on queryAllByRole because those assertions verify action visibility rather than one named action.

Behavior contract

• Delete scenarios explicitly select Delete.
• Plugin information scenarios explicitly select Plugin info.
• Update scenarios explicitly select Check for updates.
• This PR changes no production behavior and depends on fix(web): name plugin item actions #40261, which introduces the accessible names used by these locators.

Visual regression

This is a test-only PR. It has no production bundle, DOM, CSS, layout, interaction, or runtime visual effect.

Validation

• pnpm exec vp check app/components/plugins/plugin-item/tests/action.spec.tsx (0 errors, 0 warnings)
• pnpm exec vp test run app/components/plugins/plugin-item/tests/action.spec.tsx (32/32)
• pnpm check (0 errors, 2059 existing warnings)
• git diff codex/a11y-plugin-item-actions --stat (1 test file; 25 insertions, 27 deletions)

From Codex

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.41%. Comparing base (a42d785) to head (d7bbe24).

Additional details and impacted files

@@                        Coverage Diff                         @@
##           codex/a11y-plugin-item-actions   #40262      +/-   ##
==================================================================
- Coverage                           86.42%   86.41%   -0.01%     
==================================================================
  Files                                5107     5107              
  Lines                              290752   290734      -18     
  Branches                            57923    57917       -6     
==================================================================
- Hits                               251270   251251      -19     
- Misses                              34541    34542       +1     
  Partials                             4941     4941              

Flag	Coverage Δ
dify-ui	93.49% <ø> (ø)
web	86.11% <ø> (-0.01%)	⬇️

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