impl Convert to explicit imports #1589

[asukaminato0721]

Summary

Fixes part of #1589

Implemented “Convert to explicit imports” as a refactor code action: it locates the selected from ... import *, resolves actual used names via bindings, rewrites the import line (preserving indentation and trailing comments), wires it into LSP capabilities.

Test Plan

Adds coverage tests.

[Copilot]

Pull request overview

This PR implements the "Convert to explicit imports" refactoring code action to help developers replace wildcard imports (from ... import *) with explicit imports listing only the names actually used in the code. This addresses part of issue #1589 for feature parity with Pylance/Basedpyright.

Changes:

• Adds new refactor code action that converts star imports to explicit import lists by analyzing bindings
• Registers new "refactor.rewrite" code action kind in LSP server capabilities
• Preserves indentation, trailing comments (like # noqa), and handles both absolute and relative imports

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pyrefly/lib/state/lsp/quick_fixes/convert_star_import.rs	Core implementation: finds star imports, collects used names via AST visitor and bindings, generates replacement text with proper formatting
pyrefly/lib/state/lsp.rs	Adds transaction method wrapper for the new code action
pyrefly/lib/state/lsp/quick_fixes/mod.rs	Declares the new module
pyrefly/lib/lsp/non_wasm/server.rs	Registers "refactor.rewrite" capability and wires the action into the code action handler
pyrefly/lib/test/lsp/lsp_interaction/basic.rs	Updates capability test expectations to include new code action kind
pyrefly/lib/test/lsp/code_actions.rs	Adds comprehensive tests covering basic usage, relative imports, multiple star imports, and no-action cases

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[yangdanny97]

I'll give this one to @kinto0 since he's been thinking about star imports for the last couple weeks ;-)

[github-actions]

According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅