Fix: strip leading asterisk decoration from block doc comments

[kivancgnlp]

Summary

• Strip a consistent leading * decoration from multiline block doc comments, matching rustdoc behavior.
• Preserve existing behavior for line docs, #[doc = "..."] attributes, *foo, and blocks without a consistent star column.
• Adjust per-line source-map offsets by the stripped byte count so doc links and syntax highlighting continue to map to the correct source ranges.

Tests Passed :

• cargo test -p hir-def
• cargo test -p ide -- hover doc_links
• cargo test -p ide -- syntax_highlighting
• cargo fmt -p hir-def -p ide -- --check
• cargo clippy -p hir-def -p ide --all-targets -- --cap-lints warn

Fixes #1759

[ChayimFriedman2]

Did you write the PR description using AI? I'm not sure you did, but if yes, please note that our AI policy forbids doing that.

[ChayimFriedman2]

Looking at the code, it's pretty clear that you used AI for the code as well without disclosing it, also contrary to our AI policy. And I'm not sure it's properly reviewed either: I am pretty sure it's possible to implement the same thing using at most half the lines, and probably with better perf.

[kivancgnlp]

Did you write the PR description using AI? I'm not sure you did, but if yes, please note that our AI policy forbids doing that.

Yes I used Claude for draft message but then I edit the message.

[ChayimFriedman2]

So, this is also disallowed. Please take notice for the next time.

[kivancgnlp]

Looking at the code, it's pretty clear that you used AI for the code as well without disclosing it, also contrary to our AI policy. And I'm not sure it's properly reviewed either: I am pretty sure it's possible to implement the same thing using at most half the lines, and probably with better perf.

Claude generated the initial code and tests. I reviewed the changes and tests by myself. I'm sorry that I discovered the policy afterward. I also evaluated possible pitfalls and alternative solutions. I’ll simplify the code.

[kivancgnlp]

• Implementation simplified
• Hover documentation was tested using a local rust-analyzer server and VS Code.
• The following behaviors were checked and verified: stars disappeared, formatting remained correct, and the documentation link worked.

[kivancgnlp]

Hi @ChayimFriedman2, just checking in on this one. As noted above, I simplified the implementation and removed the AI-generated parts entirely. The current version reflects my own review and manual testing (verified with a local rust-analyzer server and VS Code, doc-comment stars are stripped correctly, formatting stays intact, and the documentation link still resolves).

Happy to make further changes if the simplified approach still isn't the right shape. Let me know what you'd like adjusted.