fix(puzzles): restore Glacial Hollow's fire-crystal route safely

[zoeyrose]

Architecture amendment — one authored content source (2026-08-13)

Initiative atrinik/atrinik#357 supersedes every future live-branch instruction below. atrinik/content@main is the sole mutable authored source for replacement and Classic targets. Future authored changes land only on main; supported Classic artifacts are deterministically derived from the same immutable main revision. Do not create, restore, author, backport, validate, or publish through a live 1.x branch.

Exact historical 1.x commits, tags, releases, assets, preserved local snapshots, provenance, parity records, and comparisons remain valid immutable evidence. This amendment changes no other feature, balance, lore, compatibility, licensing, validation, or ownership acceptance criterion.

Parent puzzle audit: #141. Hidden-lore coordination: #142.

Outcome

Replace Glacial Hollow's player-facing development sign with an in-world, playable fire-crystal routing puzzle that teaches thermal resource planning without ever trapping the player.

The map currently contains an “under construction” sign saying scripts were removed, fire crystals should be consumed at switches to melt walls temporarily, only one may be held, random monster drops replenish them, and poor use can leave the player trapped. Related fire-crystal items/drops still exist, but no matching switch/check implementation was found.

This is restoration of an advertised-but-absent puzzle, not merely a wording cleanup.

Player loop

Use the regional premise that Nawerhals formed where fire and ice cancelled:

1. An in-world expedition notice or damaged survey explains that concentrated heat temporarily weakens particular ice seams.
2. The player obtains a fire crystal through a deterministic first source; hostile drops may supplement it but cannot be the only recovery path.
3. A nearby marked thermal socket previews which wall/route it affects and whether the route is safe to commit.
4. Applying the crystal melts a bounded wall, gives visual/audio/time feedback, and opens a route to the next safe chamber, shortcut, or optional cache.
5. A reset/reform is observable and can never cut off every exit or every replacement-crystal source.
6. The final branch yields a durable completion signal and an extension point for the Resonance Papers' high-tier field note, coordinated through chore(lore): audit hidden and discoverable world lore #142.

The intended logic tier is Tier 2 with high environmental danger. Resource pressure may be advanced, but the solution must remain readable rather than becoming random-drop attrition.

Safety model

Before implementation, draw the route as a state graph. For every wall state, show:

• all entrances and exits;
• every guaranteed and random crystal source;
• whether the player can carry, place, retrieve, or lose a crystal;
• wall melt/reform timing and feedback;
• map reset, server restart, and concurrent-party behavior;
• a no-combat fallback or emergency release if all local enemies/resources are exhausted.

Prefer one guaranteed renewable source in each potentially enclosed component, or a non-consumable emergency thaw/reset. Do not preserve the sign's one-crystal limit unless it creates meaningful routing and is proven safe in every state.

Lore integration

• Replace development prose with an Atrinik-authored expedition/survey account.
• Explain fire crystals as local thermal/resonant material without asserting that every crystal shares one origin or is inherently corrupted.
• Preserve Crystice and the region's primordial fire/ice identity.
• Expose a stable completion marker or readable location that the Resonance Papers arc can use; the puzzle must remain complete and rewarding without that optional later lore.
• Do not reveal the Incuna Presence's identity or establish a world-scale crystal retcon here.

Acceptance criteria

• The under-construction sign and its spelling errors are removed from player-facing content.
• At least one complete fire-crystal/socket/melting-wall route is playable, signposted, and resettable with visible and audible state feedback.
• The first required crystal and every recovery-critical replacement are deterministic; random hostile drops are supplementary only.
• A state-graph review proves that no wall/reset/death/resource state can remove all exits and all replacement sources.
• Crystal consumption, capacity, dropping, destruction, death, disconnect/re-entry, map reset, wall reformation, and server restart have explicit behavior.
• Two parties cannot consume each other's only recovery resource or close an ice wall onto an unrelated player without a safe release.
• The player can inspect which seam a socket controls before committing a scarce resource.
• Completion, repeat visits, and optional Resonance Papers integration are duplicate-safe.
• Existing Glacial Hollow encounters and world difficulty remain intentional; any route-danger change is coordinated with Audit progression-route danger and pilot safer travel loops #20.
• Focused catalog/world audits, map/package validation, python3 tools/validate.py, and git diff --check pass independently on main and 1.x.
• Classic runtime scenarios cover zero-crystal entry, first source, wrong socket/order, wall timeout, retreat, death, disconnect, reset, depleted monsters, server restart, completion, repeat visit, and concurrent parties.

Coordination and non-goals

• chore(lore): audit hidden and discoverable world lore #142 owns the hidden-lore audit and will link the optional scientist field note/final synthesis.
• Audit progression-route danger and pilot safer travel loops #20 owns broader route-danger policy.
• fix(puzzles): harden existing puzzle feedback, recovery, and shared state #143 owns hardening of live legacy puzzles; Glacial Hollow is separate because its advertised mechanic is not live.
• Do not make the optional lore collection mandatory for escape, replace all Glacial Hollow combat, or require a new procedural instance system.

Release lines

The stale sign, map, and related fire-crystal content are identical on main and 1.x. Author the canonical fix on main, backport separately to 1.x, and validate each line and runtime route independently.