Historical proposal: Step 11 deterministic pathfinding and movement

[MerverliPy]

Important

Historical broader proposal — not the frozen Step 11 implementation contract.

The dependency-first Step 11 candidate is deterministic spatial entity indexes and buffered position mutation. Pathfinding and autonomous movement remain excluded. Draft PR #4 proposes the canonical contract and replaces the stale synchronization blocker below. This issue remains open as historical planning evidence until that contract is reviewed.

Baseline

Step 10 deterministic grid and room topology is owner-validated complete:

• .NET SDK 8.0.129
• Step 9 dependency gate 62/62
• Step 10 final gate 72/72
• Release build 0 warnings, 0 errors
• all behavioral references PASS
• ChecksumFormatVersion = 3

Scope

Implement deterministic pathfinding and authoritative movement on top of the existing canonical one-deck grid/topology model.

Required behavior

• cardinal routes through walkable cells and doors
• deterministic tie-breaking independent of insertion/registration order
• blocked-cell avoidance
• deterministic re-path after authoritative obstruction changes
• buffered authoritative movement mutations committed through the existing Commit phase
• canonical save/load participation
• canonical global/component checksum participation
• replay and frame-pattern checksum equivalence
• concurrent route stress validation for 100 agents without deadlock

Architecture constraints

Do not create a parallel simulation runner, clock, world root, Commit phase, save envelope, persistence system, or checksum pipeline.

Explicit exclusions

• job selection and toil execution
• reservation framework
• needs and daily routines
• atmosphere simulation
• Unity presentation

These require separate milestone contracts and validation gates.

Completion gate

Completion requires an owner transcript showing:

1. exact prior gate 72/72 passes before apply;
2. scoped payload integrity and source guards pass;
3. all behavioral references pass;
4. Release build succeeds with 0 warnings, 0 errors;
5. the expanded exact harness passes;
6. deterministic save/load, replay, frame-pattern, obstruction churn, and concurrent-route tests pass;
7. backup and rollback artifacts are recorded.

Blocking synchronization issue

The GitHub repository was empty when this issue was created. The validated executable source at /home/calvin/Generation-Ark/generation-ark-clock must be pushed before implementation can proceed safely through GitHub.