S3-027: Implement individual settlers and spatial movement

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

Assign stable identities and occupations. Track real location and action state. Implement six-direction movement and occupancy.

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

• Assign stable identities and occupations.
• Track real location and action state.
• Implement six-direction movement and occupancy.
• 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

• Move agents across all directions.
• Verify blocked tiles and identity persistence.
• 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/28

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.

Completed: individual settlers and spatial movement

• Stable identities and occupations: every settler has an id, owner, profession, tool, program and diagnostic (resources/game/engine/settlers.ts). Profession changes are counted in the ledger's transitions; ids survive save/restore.
• Real location and action state: tile position, next tile, step progress, direction and action (idle, walking, working, inside) are simulation state; the renderer interpolates only for drawing.
• Six-direction movement and occupancy: movement follows the reference remake's six-direction lattice. Engineering decision, recorded in the code: walking settlers pass each other as crowds do on the original screen, while each resting settler holds a distinct tile and steps to a free one when it stops on a held tile. Placement refuses sites where settlers rest.

Tests: a settler walks one step in each of the six directions back to its origin with the expected direction values and identity; blocked tiles are routed around; occupancy is audited every five ticks in a 12,000-tick economy (tests/unit/engine-audit.test.ts). Movement timings are placeholders owned by this issue's fidelity follow-up in S3-007.

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.