Add VS Code and VS Code Insiders as skill-supporting clients

[samuv]

Summary

Enables VS Code and VS Code Insiders (GitHub Copilot) as skill-supporting clients alongside claude-code, codex, opencode, and cursor.

Both variants run the same GitHub Copilot extension and share the same skill directories:

• Personal skills: ~/.copilot/skills/<name> (user scope)
• Project skills: <project>/.github/skills/<name> (project scope)

Paths sourced from the VS Code Agent Skills docs. No platform prefix is needed — unlike VS Code's MCP config (which lives under Library/Application Support or .config/Code/), the skills dirs are a flat ~/.copilot/ and .github/ on all platforms.

Type of change

• New feature

Test plan

• Unit tests (task test)
• Linting (task lint-fix)

Changes

File	Change
pkg/client/config.go	Add SupportsSkills, SkillsGlobalPath, SkillsProjectPath to both the VS Code and VS Code Insiders entries
pkg/client/skills_test.go	Update fixtures, add TestSupportsSkills cases, bump list count to 7, add path test cases for both clients
pkg/client/discovery_test.go	Update VS Code fixture and flip SupportsSkills assertion

Does this introduce a user-facing change?

Yes — thv skill install --clients vscode and thv skill install --clients vscode-insider (or --clients all) now work. Skills land in ~/.copilot/skills/ so GitHub Copilot picks them up automatically in both VS Code variants.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 68.92%. Comparing base (6a79259) to head (a9e2657).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4773      +/-   ##
==========================================
- Coverage   68.94%   68.92%   -0.02%     
==========================================
  Files         517      517              
  Lines       54741    54741              
==========================================
- Hits        37742    37732      -10     
- Misses      14095    14107      +12     
+ Partials     2904     2902       -2     

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