v0.9.9 - macOS notification on task done

What's New

• macOS native notification when a task moves to done — triggers via osascript with Glass sound
• Fix hook matcher from mcp__cortex__task_update to mcp__cortex__task (unified MCP tool with action parameter)
• LSP reindex on edit for Elixir files (.ex/.exs) via PostToolUse hook
• Conventional commits validation hook for Bash pre-tool-use
• Bump version to 0.9.9