Closes D1. Both T5 zones follow the D1-a/b/c/d pattern: extend the
graph so the longest entry→boss walk lands in band, keep the zone's
authored topology intact. Also backfills the missing per-node
RegionID authoring against dnd_expedition_region.go — the D1-d
deferral note flagged this as a prerequisite for T5.
dragons_lair (T5): 12 → 47 nodes, longest 38 (band 36-44)
abyss_portal (T5): 13 → 51 nodes, longest 39 (band 36-44)
Topology preserved per zone:
- Dragon's Lair: 4-region authoring (every node carries a valid
RegionID); binary-converging fork1 (ash_bridge TRAP / treasure_vault
Perception 15) still converges at the R3 wyrmlings_nest elite;
capstone fork2 still 3-way (LockNone / CHA 16 / Perception 17
SECRET LootBias 2.5) with each spur preserving its own named
capstone node. New R4 infernax_doors MERGE consolidates the long
final hall instead of triplicating it.
- Abyss Portal: 4-region authoring; three sequential forks preserved
(binary / binary / ternary) — fork1 Perception 16, fork2 CON 16
(full STR/DEX/CON/INT/WIS/CHA roster still covered), fork3 capstone
3-way with reality_seam SECRET LootBias 3.0. New R4 belaxath_doors
MERGE consolidates the final tear-approach.
MinRooms/MaxRooms re-pitched 9-10 → 36-44 so the dice fallback also
lands in band for any future graphless variant.
T5 zone, seventh authored graph. Shape: long approach (kobold_warrens
→ drake_pens) → binary mid-fork that converges at the elite
(wyrmlings_nest) → 3-way capstone fork into the boss
(direct / CHA bargain / Perception-found hoard_pillar secret).
First zone combining two distinct fork stages where the first converges
diamond-style and the second spreads triple-wide. Secret carries
LootBias 2.5 — highest of any shipping zone, reserved for T5 — locked
in by TestDragonsLairGraph_LootBiasEscalation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>