Replace VSCode-specific documentation links in hover responses with neovim-compatible navigation instructions

[Copilot]

Problem

Hover responses from the F# language server contain VSCode-specific command links that are unusable in neovim:

<a href='command:fsharp.showDocumentation?%5B%7B%20%22XmlDocSig%22%3A%20%22P%3AProgram.server%22%2C%20%22AssemblyName%22%3A%20%22AppHost%22%20%7D%5D'>Open the documentation</a>

These links appear in hover documentation but don't work in neovim, leaving users with broken functionality where they can't navigate to symbol definitions.

Solution

This PR modifies the textDocument/hover handler to automatically replace VSCode-specific documentation command links with helpful neovim navigation instructions.

Before:

val server: IResourceBuilder<ProjectResource>

<a href='command:fsharp.showDocumentation?...'>Open the documentation</a>
*Full name: Program.server*
*Assembly: AppHost*

After:

val server: IResourceBuilder<ProjectResource>

**Go to definition** (place cursor on symbol and use `gd` or `<C-]>`)
*Full name: Program.server*
*Assembly: AppHost*

Implementation Details

• Modified hover handler: Updated textDocument/hover to process response content and replace documentation links
• New replacement function: Added _replace_documentation_links() that parses VSCode command URLs and replaces them with actionable neovim instructions
• Preserved existing functionality: All other hover content (type signatures, metadata) remains unchanged
• Comprehensive testing: Added full test suite covering link parsing, replacement, and integration scenarios
• Test helpers: Exposed internal functions for testing while maintaining clean public API

Benefits

• ✅ Removes unusable VSCode-specific command links
• ✅ Provides clear, actionable navigation instructions for neovim users
• ✅ Uses neovim's built-in LSP "go to definition" functionality (gd, <C-]>)
• ✅ Maintains backward compatibility
• ✅ Preserves all existing hover content and formatting
• ✅ Fully tested with edge cases covered

Users can now use standard neovim LSP navigation instead of seeing broken links. When they want to go to a symbol's definition, they simply place their cursor on the symbol and press gd or <C-]>, which is the standard neovim way to navigate to definitions.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• esm.ubuntu.com
  • Triggering command: /usr/lib/apt/methods/https (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.