Validate POC A and POC B foundations

AGENTS.md

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+# Ransom's Wake — Repository rules
+
+These rules apply to the whole repository. They are mandatory for human and AI
+contributors.
+
+## Read before changing code
+
+1. Read `docs/ENGINEERING_GUARDRAILS.md`.
+2. Read the relevant technical baseline under `docs/`.
+3. Check `docs/adr/` for decisions affecting the change.
+
+## Prototype boundary
+
+- `src/` and `scenes/` contain the disposable POC A/B implementation.
+- They may be changed only for an explicitly requested prototype correction.
+- Production code must not import, extend, copy, or silently promote code from
+  `src/` or `scenes/`.
+- Reuse a validated behavior by rewriting it behind a production contract and
+  by linking the relevant baseline in the change description.
+
+## Production boundary
+
+New production code belongs under `game/` and follows these dependency rules:
+
+- `game/domain/`: pure rules and typed data; depends on no other game layer.
+- `game/application/`: use cases and ports; may depend only on `domain`.
+- `game/world/`: Godot actors and physics adapters; may depend on `application`
+  and `domain`.
+- `game/presentation/`: HUD and rendering; may depend on `application` and
+  read-only domain data.
+- `game/infrastructure/`: saves, audio, platform and input adapters; may depend
+  on `application` and `domain`.
+- `game/composition/`: scene assembly; this is the only layer allowed to wire
+  all other layers together.
+
+Do not create a generic `utils`, `helpers`, `common`, or `shared` dumping ground.
+Reusable behavior must have one named owner in the layer responsible for it.
+
+## Implementation rules
+
+- One authoritative implementation per concept.
+- Use typed objects or resources across production boundaries, not anonymous
+  dictionaries with implicit keys.
+- UI and renderers never calculate gameplay rules or mutate world state
+  directly; they issue application commands and consume snapshots/events.
+- Domain code does not access `Input`, the scene tree, rendering, audio, files,
+  clocks, or random global state.
+- Randomness and time-dependent behavior must be injectable and deterministic
+  in tests.
+- New autoloads, cross-layer dependencies, save-format changes, or exceptions to
+  these rules require an ADR in `docs/adr/`.
+- A bug fix requires a regression test unless the behavior cannot reasonably be
+  automated; document that exception.
+
+## Required verification
+
+Run this command before declaring a code change complete:
+
+```sh
+bash scripts/quality_gate.sh
+```
+
+Do not weaken, skip, or delete a failing check to make a change pass. Fix the
+cause or record an explicit architectural decision.