feat(linter/always-return): implement promise rule always-return

[lambda47]

Related to #4655

[graphite-app]

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13178 will not alter performance

_{Comparing lambda47:feature/linter_promise_always-return_rule (40a641f) with main (06ec43c)}

Summary

✅ 34 untouched benchmarks

[Copilot]

Pull Request Overview

This PR implements a new ESLint rule promise/always-return that enforces proper return values in Promise .then() callbacks to prevent broken Promise chains. The rule ensures that each .then() callback either returns a value or throws an exception.

Key Changes:

• Implements the AlwaysReturn rule with comprehensive logic for analyzing Promise callback control flow
• Adds configuration options for ignoreLastCallback and ignoreAssignmentVariable settings
• Includes extensive test coverage with snapshot testing for various Promise chain scenarios

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
crates/oxc_linter/src/rules/promise/always_return.rs	Complete implementation of the always-return rule with control flow analysis
crates/oxc_linter/src/snapshots/promise_always_return.snap	Snapshot test file containing expected diagnostic outputs
crates/oxc_linter/src/rules.rs	Module registration to include the new rule in the linter

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[camc314]

thanks