feat: add progressive discovery for routine suggestions
chat_context.py pre-hook counts behavioral trigger signals per template
on every conversation. When trigger thresholds are met and all five
eligibility gates pass (suggestions enabled, naming ceremony complete,
no active routine for template, not declined, 7-day cooldown), a hint
section is injected into the system prompt.
New CLI commands: suggest-respond records accepted/declined responses,
suggest-state returns suggestion state as JSON. Delete command resets
accepted suggestion state when a routine is removed.
Muse prompt gains progressive discovery guidance for natural,
observation-framed suggestions with strict etiquette rules.