Add obsidian-high-recall skill

[ToussaintKnight]

Adds obsidian-high-recall to Specialized Skills.

Why it fits this list:

• It is a Codex skill with a SKILL.md bundle and CLI wrapper.
• It is directly useful for Codex users who keep research or project context in private Obsidian vaults.
• It has a clear unique value: high-recall local retrieval, Smart Connections vector reuse when available, local hybrid fallback, and no raw note upload.

I placed it near the existing memory/search-related skill entries and included the required GitHub star badge.