- Encounter entity; Combatant now belongs to an encounter (ON DELETE
CASCADE). Migration adds encounter_id, rehoming any existing combatants.
- /tracker lists encounters (name, count, last updated) with a "New
encounter" form; /tracker/{id} is the HP tracker for one encounter.
- Encounters can be renamed, have their combatants cleared, or be deleted.
- The Enemies list gains an encounter picker next to "Add to tracker"
(existing encounter or "— New encounter —", which prompts for a name);
an encounter's "Add enemies" link pre-selects it via ?encounter=.
- Routes for combatant HP/remove moved under /tracker/combatant/ to keep
the numeric {id} for encounters.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
