Add custom-food and log commands

[milldr]

Summary

• Adds crono add custom-food <name> command to create named custom foods in Cronometer with macros and auto-calculated calories
• Adds crono log <name> command to search for any saved food by name and log it to the diary
• Both commands use Kernel.sh browser automation with Playwright codegen
• Calories are auto-calculated from macros (P×4 + C×4 + F×9) or set explicitly with -t/--total
• add custom-food supports --log [meal] to create and log in one step
• Graceful error handling for Cronometer login rate limiting
• GWT constants documented as public artifacts in src/cronometer/auth.ts

New Commands

crono add custom-food <name>

crono add custom-food "Chicken Sandwich" -p 50 -c 100 -f 50
crono add custom-food "Chicken Sandwich" -p 50 -c 100 -f 50 -t 1000
crono add custom-food "Chicken Sandwich" -p 50 -c 100 -f 50 --log Dinner

crono log <name>

crono log "Chicken Sandwich" -m Dinner
crono log "Chicken Sandwich" -m Snacks -s 2

Files Changed

• src/kernel/add-custom-food.ts — Playwright codegen for custom food creation
• src/kernel/log-food.ts — Playwright codegen for food search + diary log
• src/kernel/client.ts — New interfaces and KernelClient methods
• src/kernel/login.ts — Rate limit detection on failed login
• src/commands/add.ts — add custom-food command handler
• src/commands/log.ts — log command handler
• src/index.ts — Command registration
• src/cronometer/auth.ts — GWT constants comment
• README.md — Documentation for new commands
• CLAUDE.md — Build reminder for development

Test plan

• Unit tests pass (165 tests across 18 files)
• Lint and format checks pass
• Live tested add custom-food with macros and auto-calculated calories
• Live tested log with meal category
• Verified food name, macros, and calories saved correctly in Cronometer