Summary

• Add hooks/caveman-config.js — shared config resolver with XDG-compliant path resolution across all platforms
• Remove hard-coded 'full' default from caveman-activate.js and caveman-mode-tracker.js, replaced with getDefaultMode() call
• Update install.sh to include the new config module

Config resolution order

1. CAVEMAN_DEFAULT_MODE environment variable (highest priority)
2. Config file defaultMode field at:
   • $XDG_CONFIG_HOME/caveman/config.json (any platform, if XDG_CONFIG_HOME is set)
   • ~/.config/caveman/config.json (macOS / Linux fallback)
   • %APPDATA%\caveman\config.json (Windows fallback)
3. 'full' (unchanged default)

Example config

{ "defaultMode": "ultra" }

Or per-harness via environment variable:

CAVEMAN_DEFAULT_MODE=lite

Test plan

Manual smoke tests — all passing:

Test 1: No config (default behavior)

$ node -e "const c = require('./hooks/caveman-config'); console.log('default:', c.getDefaultMode()); console.log('configPath:', c.getConfigPath()); console.log('configDir:', c.getConfigDir());"
default: full
configPath: /Users/matt/.config/caveman/config.json
configDir: /Users/matt/.config/caveman

Test 2: Environment variable override

$ CAVEMAN_DEFAULT_MODE=ultra node -e "const c = require('./hooks/caveman-config'); console.log('default:', c.getDefaultMode());"
default: ultra

Test 3: XDG config file override

$ mkdir -p /tmp/caveman-xdg-test/caveman
$ echo '{"defaultMode":"lite"}' > /tmp/caveman-xdg-test/caveman/config.json
$ XDG_CONFIG_HOME=/tmp/caveman-xdg-test node -e "const c = require('./hooks/caveman-config'); console.log('default:', c.getDefaultMode());"
default: lite

Validation

• No config → defaults to full (backward compatible)
• CAVEMAN_DEFAULT_MODE env var respected
• XDG config file with defaultMode respected
• Invalid modes in config/env are ignored (falls through to default)