Populate the Stage

entity token UI on the Stage show page. Party column (campaign characters → PC tokens, HP auto-seeded from max_hp CharacterAttribute via snapshot model); NPC column (campaign articles with kind: npc → NPC tokens, label + portrait from subject); Monsters column (5e SRD API typeahead via monster_search Stimulus controller + server-side proxy at GET /stages/:id/monster_search). StageToken#before_create seeds label and HP from the linked subject. MonsterSearchTool MCP tool (126 total). ADR-0050 written. Seeds updated with Lyra, Theron, Marta Vance, and a seeded Goblin token.