S3-026: Instantiate original terrain, elevation, and map geometry

Parent and ownership

Parent epic: https://github.com/stacksjs/the-settlers-iii-remake/issues/7 Source owner: stacksjs/the-settlers-iii-remake. Master roadmap: https://github.com/stacksjs/the-settlers-iii-remake/issues/4.

Problem and observable result

Create worlds from imported maps. Align projection, slopes, picking, and entrances. Derive correct traversability and footprints.

The current application is a browser prototype. Passing the Riverlands campaign does not establish original-game or native parity. This issue is complete only when its stated behavior has retained evidence.

Evidence and interfaces

Ordered commands advance an integer-tick world. Goods have locations and reservations, people have identities and jobs, and a player view renders only actual simulation state.

• https://github.com/JakeSteam/settlers/blob/8426388935b436e65b0697ac401c4247ab097364/en/ec_basic/basics.htm
• https://github.com/JakeSteam/settlers/blob/8426388935b436e65b0697ac401c4247ab097364/en/ec_build/building.htm

Pin the inspected revisions and fixture hashes in the implementation evidence. Original-game observations govern rules and timing. JSettlers is implementation evidence, not an authoritative balance specification. Unknown values remain explicitly unverified.

Acceptance criteria

• Create worlds from imported maps.
• Align projection, slopes, picking, and entrances.
• Derive correct traversability and footprints.
• The visible result agrees with the underlying simulation or platform state, including failure paths.
• Tests exercise the maintained public interface and retain reproducible fixtures or execution receipts.

Test matrix

• Round-trip picking across elevations.
• Validate representative original maps.
• Exercise invalid input, cancellation or interruption, and repeated execution where this interface permits them.
• Verify determinism/conservation for simulation changes and resource ownership/disposal for platform changes.
• Run owning-repository lint, relevant type checks and tests. Capture actual native output for native capability claims.

Scope constraints

Implement this behavior as a complete verifiable slice. Do not silently expand into adjacent tickets or substitute simplified gameplay. Keep the shared TypeScript simulation, shared stx signals, and ts-css conventions. Native gameplay and HUD must not depend on a WebView. HomeOS reuse must not introduce a kernel dependency into the game. Existing unrelated edits and authored guidance must be preserved.

Blocked by

• https://github.com/stacksjs/the-settlers-iii-remake/issues/22
• https://github.com/stacksjs/the-settlers-iii-remake/issues/27

Upstream release and adoption

Application behavior belongs here. If a reproduction identifies a framework defect, repair and release its owning source first, update Stacks where affected, then install the verified packages here.

No node_modules edits, copied runtimes, generated-source string patches, fabricated globals, successful no-op implementations, or skipped release gates. Push tested conventional commits as Chris to the owning origin/main without coauthor trailers or force pushes.

Completion evidence

• Implementation commits and relevant upstream issue links.
• Exact checks and results, fixture hashes, and screenshots/native execution evidence where applicable.
• Published package versions, downstream lockfile identity, and release receipts when affected.
• Remaining limitations stated explicitly. Partial work does not close this issue.

Progress: original terrain, elevation and map geometry (still open)

• worldFromOriginal() creates engine worlds from decoded original maps: landscape codes map to terrain classes through the reference remake's OriginalLandscape table, heights scale as the reference scales them, classified trees and stones become objects, deposits keep their original amounts, and each Roman or free-choice player's buildings, settlers and piles become scenario state. Unsupported civilizations, soldiers and unclassified objects are counted, not approximated. All three demo maps build sessions that conserve goods and round-trip saves (tests/unit/engine-original.test.ts).
• Projection follows the reference coordinate converter; elevation-aware picking round-trips on sloped ground; doors, protected rings and pile positions come from the reference definitions.

Left open because traversability classes, slope limits and footprints are reference-remake evidence that still needs comparison with original observations (S3-002), and only demo maps are available.

Evidence base for this update (all on main, authored as Chris):

• 3ca4847 deterministic session, rules profile, routing, goods, carriers, construction, production, territory, visibility, saves and replays
• da2a104 reference building geometry and the delivery livelock fix
• b2efc1f the browser game on the engine, expanded original-media import
• 7b1cc36 worlds from decoded original maps
• a495e7a, 0a3ff46, 0e7889e, e5c1a53, f3b71ce, ed1dc8f controls, missions, render scene, save migration, checkpoints, audit and statistics

Checks: ./buddy lint (0 problems), bun run typecheck (app, tools, stx), ./buddy test --unit (106 tests, 0 failures), bun run assets:verify, bun run content:verify, and the production browser scenario. CI passed on 0e7889e and 9e2ba7c (which contains f3b71ce), including the production Chrome check.

Rule values are the roman-engineering 0.2.0 profile (resources/game/engine/rules.ts). Every value names its evidence class: manual candidates (M) from the pinned manual, reference-remake geometry (E), or placeholders (U) that name their owning issue. qualificationGaps() lists them and the profile cannot qualify a release. Adopting observed original values remains with S3-002/S3-007; nothing here is an original-executable observation.

Completed #219: all 37 reference landscape identities and 29 original codes now survive conversion and the existing versioned terrain indices. Rivers are traversable land, sea depths remain water, and source ground/resource groups drive placement and production. Unsupported codes produce structured source-code and coordinate evidence. Mixed-face rendering continues in #220; complete terrain and Gold qualification remain open.

Validation: full CI, 413 unit tests and all 16 browser suites. The original diagnostic artifact checksum and ZIP integrity were independently verified.