Description

• Closes feat(node): export capturePrintError #10253 (supersedes)
• Closes refactor: remove redundant task from error print options #10259 (supersedes)

This PR adds ctx.logger.formatError(error, options) as a side-effect-free counterpart to ctx.logger.printError(...). Custom reporters can now reuse Vitest’s existing error formatting while writing the formatted output to their own sinks.

This change also removes the redundant options.task field, which leaked the internal runner task type into error formatting options. It was used for branching browser mode stack formatting but another option options.project is sufficient for the same purpose. Also, as a part of the migration, the built-in GitHub Actions and JUnit reporters now use logger.formatError.

Here are some other ways to expose the same API. I ended up with logger.formatError as it seems most natural place.

• A top-level formatError(error, ctx, options) export would be simple, but it would introduce a new standalone reporter utility surface and still need ctx for config, stack filtering, source maps, browser parsing, and highlighting.

• ctx.formatError(error, options) would avoid a top-level export, but error formatting is logger/reporting behavior rather than core Vitest orchestration behavior.

• static DefaultReporter.formatError(error, ctx, options) would keep the helper near reporter APIs, but formatting is not specific to DefaultReporter, and it would still need ctx.

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