[toast] Prevent duplicate onClose calls for ending toasts

[chuganzy]

This PR fixes an issue where onClose could be triggered multiple times when a toast is already in the ending state as pointed out here.

• I have followed (at least) the PR section of the contributing guide.

[pkg-pr-new]

• base-ui-tanstack-start

• vite-css-base-ui-example

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/react@4280
  

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/utils@4280
  

commit: bf74137

[mui-bot]

Bundle size report

Bundle	Parsed size	Gzip size
@base-ui/react	🔺+10B(0.00%)	▼-7B(0.00%)

Details of bundle changes

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[atomiks]

Codex Review

Overview

This patch now updates toast state before running onClose, and it extends the regression test so a toast can call close() from inside onClose without double-firing. The branch stays narrowly focused on the toast close path and the new test coverage matches the bug being fixed.

Findings (None)

No blocking issues found in this patch.

Confidence: 5/5

High confidence based on the full branch diff, the narrow implementation surface, and focused verification of the shared toast-manager code path.

Notes

• Re-ran pnpm test:jsdom createToastManager --no-watch on the PR head.
• Re-ran pnpm test:jsdom useToastManager --no-watch on the PR head.
• The latest commit addresses the earlier re-entrant onClose concern by moving the callback after the state update and by strengthening the regression test to cover that sequence.

[chuganzy]

This function is the only one with a side effect, so I moved it below to keep the order unchanged.
The execution order remains onClose → focus update (onFocus / onBlur).

Although this depends on the state internally, it only looks up the next (or prev) active toast, so I believe changing the position should not cause any issues.