feat(install): add --add-skill and --add-mcp for direct module installation

[b33eep]

Summary

• Add --add-skill <name> for non-interactive skill installation
• Add --add-mcp <name> for non-interactive MCP server installation
• Add reconcile_tracking() to sync installed.json with filesystem during --update
• Update /claude-code-setup command to use the new options

Problem

The /claude-code-setup command had to use fragile stdin-based interaction (printf 'none\n2\nn\n' | install.sh --add) to install modules. Module numbers were dynamic, making reliable installation impossible.

Additionally, modules installed before tracking existed or installed manually were never tracked in installed.json, causing them to be skipped during updates.

Solution

1. Direct installation options: --add-skill standards-kotlin and --add-mcp pdf-reader work without any user interaction
2. Tracking reconciliation: reconcile_tracking() runs at the start of --update to sync installed.json with what's actually on disk

Test plan

• ./tests/test.sh 22-add-skill - Direct skill installation
• ./tests/test.sh 23-add-mcp - Direct MCP installation
• ./tests/test.sh 24-reconcile - Tracking reconciliation
• ./tests/test.sh - All 27 scenarios pass

Usage

# Install skill directly
./install.sh --add-skill standards-kotlin
./install.sh --add-skill custom:my-skill

# Install MCP directly
./install.sh --add-mcp pdf-reader
./install.sh --add-mcp custom:my-mcp