fix(core): preserve options when restarting

[chenjiahan]

Summary

JavaScript API restarts previously fell back to the default build() or startDevServer() options. This PR snapshots the original options, exposes them through the action-specific RestartContext, and reuses them when the CLI restarts the task. It also updates the related documentation and regression coverage.

[coderabbitai]

📝 Walkthrough

Walkthrough

Restart contexts now include the options used by the triggering build or development-server operation. Core restart handling preserves these options and adds watched file paths, while CLI restart execution reuses them. The RestartContext type and API documentation were updated accordingly. Unit and end-to-end tests now validate empty options, watched builds, and development-server option preservation.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly matches the main change: preserving restart options in core restart flow.
Description check	✅ Passed	The description accurately summarizes the option-preservation fix, restart context changes, and doc/regression updates.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

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• Create stacked PR
• Commit on current branch

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@website/docs/en/shared/onRestart.mdx`:
- Line 34: Update the options description in
website/docs/en/shared/onRestart.mdx at line 34 to mention
rsbuild.createDevServer() alongside rsbuild.startDevServer(), clarifying that
only StartDevServerOptions-compatible fields are exposed; apply the equivalent
clarification in website/docs/zh/shared/onRestart.mdx at line 34.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7e62ff10-95b6-4a81-be6c-4ba4aec2b809

📥 Commits

Reviewing files that changed from the base of the PR and between 44805db and ec3d43b.

📒 Files selected for processing (16)

• e2e/cases/javascript-api/dev-server-restart/index.test.ts
• e2e/cases/javascript-api/restart-option/index.test.ts
• e2e/cases/javascript-api/restart-preserve-options/index.test.ts
• e2e/cases/javascript-api/restart-preserve-options/src/index.js
• e2e/cases/javascript-api/restart-watch-files/index.test.ts
• packages/core/src/build.ts
• packages/core/src/cli/init.ts
• packages/core/src/createRsbuild.ts
• packages/core/src/restart.ts
• packages/core/src/server/devServer.ts
• packages/core/src/types/hooks.ts
• packages/core/tests/restartHook.test.ts
• website/docs/en/api/javascript-api/core.mdx
• website/docs/en/shared/onRestart.mdx
• website/docs/zh/api/javascript-api/core.mdx
• website/docs/zh/shared/onRestart.mdx