Add story-graph narrative system (campaigns, editors, runtime)

Introduce the narrative layer as a directed story-flow graph: an authored
campaign a player walks node by node, replacing the interim slot/chapter model.

Schema (migrations 015-021):
- mysteries, global NPC templates + named poses, per-user playthroughs
- story_nodes, terminals, utterances (the flow graph and dialogue trees)
- clean cutover: retire slot cutscenes/chapters/seen_dialogue

Runtime:
- New Game creates a playthrough bound to the JWT identity (dev test-user fallback)
- advance() walks the graph cutscene -> dialogue -> level -> ..., auto-skipping gates
- branching dialogue: player choices route out through node terminals

Admin authoring:
- NPC editor: upload named poses to the gupi MinIO bucket
- mystery graph editor: vertical node canvas, wiring, entrypoint, delete-by-click
- dialogue crafter: utterance tree, Tab to add child, 1/2 speaker, undo

Content authored via the manifest importer / admin panel and seeded for Glass
Harbour. MinIO added to the dev stack; dev container runs in development mode.

Also includes a folder-widget simplification (removes open/close) and a
resolveUserId auth helper.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

migrations/017_global_npc_templates.sql

@@ -0,0 +1,10 @@
+-- NPCs become a reusable, global template library rather than per-mystery copies.
+-- A NULL mystery_id marks a global template; mysteries reference templates by key
+-- when authored, so editing an NPC in the admin panel survives re-imports.
+ALTER TABLE osint.npcs ALTER COLUMN mystery_id DROP NOT NULL;
+
+-- Enforce one global template per key (the existing UNIQUE(mystery_id, npc_key)
+-- does not constrain rows where mystery_id IS NULL).
+CREATE UNIQUE INDEX npcs_global_key_idx ON osint.npcs (npc_key) WHERE mystery_id IS NULL;
+
+COMMENT ON TABLE osint.npcs IS 'Reusable NPC templates. mystery_id IS NULL for a global template; mysteries reference templates by npc_key when authored.';