Utterance award + requirement, and branching dialogue seeding

A dialogue line can award an achievement when reached (granted server-side,
validated against the player's current node so it can't be forged) and an
option can require an achievement to be offered (filtered out of the resolved
tree otherwise). authorGraph gains a branching form (utterance key/parent/
terminal) so option trees — not just linear lines — can be seeded. This is
gaps 1 & 2 for the Barricelli Dobby/Glitch-Hunter dialogues; phone dialing
stays stubbed.

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

scripts/importMysteryTemplate.ts

@@ -19,7 +19,7 @@ type MysteryGraph = {
   nodes: { key: string; type: 'cutscene' | 'dialogue' | 'level' | 'det_gate' | 'llm_gate' | 'merit' | 'phone'; label?: string; x: number; y: number
     componentKey?: string; templateSlug?: string; version?: number; awardsFlag?: string
     terminals?: { key: string; label?: string; to?: string | null; npc?: string }[]
-    utterances?: { npc?: string; pose?: string; text: string; utterer?: 'npc' | 'player' }[] }[]
+    utterances?: { key?: string; parent?: string; terminal?: string; npc?: string; pose?: string; text: string; utterer?: 'npc' | 'player'; awardsFlag?: string; requiresFlag?: string }[] }[]
 }
 type MysteryNarrative = {
   cast: { key: string; name: string; role?: string; defaultPose?: string; phoneNumber?: string; email?: string; poses?: { poseKey: string; assetId: string }[] }[]