T001–T006: Phase 1 setup (workspace, Biome, TS, Vitest, layer boundary enforcement)

.gitignore

@@ -0,0 +1,13 @@
+node_modules/
+dist/
+build/
+*.log
+.env*
+.DS_Store
+Thumbs.db
+*.tmp
+*.swp
+.vscode/
+.idea/
+coverage/
+*.tsbuildinfo

.nvmrc

@@ -0,0 +1 @@
+22

.specify/memory/constitution.md

@@ -1,50 +1,145 @@
-# [PROJECT_NAME] Constitution
-<!-- Example: Spec Constitution, TaskFlow Constitution, etc. -->
+<!--
+  Sync Impact Report
+  ───────────────────
+  Version change: 1.0.2 → 1.0.3 (PATCH — add merge-gate rule)
+  Modified sections:
+    - Development Workflow: added automated-checks merge gate
+  Templates requiring updates:
+    - .specify/templates/plan-template.md        ✅ no update needed
+    - .specify/templates/spec-template.md         ✅ no update needed
+    - .specify/templates/tasks-template.md        ✅ no update needed
+  Follow-up TODOs: none
+-->
+# Encounter Console Constitution
 
 ## Core Principles
 
-### [PRINCIPLE_1_NAME]
-<!-- Example: I. Library-First -->
-[PRINCIPLE_1_DESCRIPTION]
-<!-- Example: Every feature starts as a standalone library; Libraries must be self-contained, independently testable, documented; Clear purpose required - no organizational-only libraries -->
+### I. Deterministic Domain Core
 
-### [PRINCIPLE_2_NAME]
-<!-- Example: II. CLI Interface -->
-[PRINCIPLE_2_DESCRIPTION]
-<!-- Example: Every library exposes functionality via CLI; Text in/out protocol: stdin/args → stdout, errors → stderr; Support JSON + human-readable formats -->
+All domain logic MUST be implemented as pure state transitions.
+Given the same input state and action, the output state MUST be
+identical across runs. Side effects (I/O, randomness, clocks) MUST
+be injected at the boundary, never sourced inside the domain layer.
 
-### [PRINCIPLE_3_NAME]
-<!-- Example: III. Test-First (NON-NEGOTIABLE) -->
-[PRINCIPLE_3_DESCRIPTION]
-<!-- Example: TDD mandatory: Tests written → User approved → Tests fail → Then implement; Red-Green-Refactor cycle strictly enforced -->
+- State transitions MUST be expressed as pure functions.
+- Random values (e.g., dice rolls) MUST be passed in as resolved
+  inputs, not generated within the domain.
+- Domain functions MUST NOT depend on wall-clock time, network, or
+  filesystem.
 
-### [PRINCIPLE_4_NAME]
-<!-- Example: IV. Integration Testing -->
-[PRINCIPLE_4_DESCRIPTION]
-<!-- Example: Focus areas requiring integration tests: New library contract tests, Contract changes, Inter-service communication, Shared schemas -->
+### II. Layered Architecture
 
-### [PRINCIPLE_5_NAME]
-<!-- Example: V. Observability, VI. Versioning & Breaking Changes, VII. Simplicity -->
-[PRINCIPLE_5_DESCRIPTION]
-<!-- Example: Text I/O ensures debuggability; Structured logging required; Or: MAJOR.MINOR.BUILD format; Or: Start simple, YAGNI principles -->
+The codebase MUST be organized into four layers with strict
+dependency direction:
 
-## [SECTION_2_NAME]
-<!-- Example: Additional Constraints, Security Requirements, Performance Standards, etc. -->
+1. **Domain** — pure types, state transitions, validation rules.
+   No imports from other layers.
+2. **Application** — orchestrates domain operations, manages
+   workflows, coordinates use cases. Application defines port
+   interfaces that Adapters implement. May import Domain only.
+3. **Adapters** — I/O, persistence, UI rendering, external APIs.
+   May import Application and Domain.
+4. **Agent** — AI-assisted features (suggestions, analysis).
+   May import Application and Domain as read-only consumers.
 
-[SECTION_2_CONTENT]
-<!-- Example: Technology stack requirements, compliance standards, deployment policies, etc. -->
+A module in an inner layer MUST NOT import from an outer layer.
 
-## [SECTION_3_NAME]
-<!-- Example: Development Workflow, Review Process, Quality Gates, etc. -->
+### III. Agent Boundary
 
-[SECTION_3_CONTENT]
-<!-- Example: Code review requirements, testing gates, deployment approval process, etc. -->
+The agent layer MAY read domain events and current state. The agent
+MAY produce suggestions, annotations, or recommendations. The agent
+MUST NOT mutate domain state directly. All agent-originated changes
+MUST flow through the Application layer as explicit user-confirmed
+commands.
+
+- Agent output MUST be clearly labeled as suggestions.
+- No silent or automatic application of agent recommendations.
+
+### IV. Clarification-First
+
+Before making any non-trivial assumption during specification,
+planning, or implementation, the agent MUST surface a clarification
+question to the user. "Non-trivial" means any decision that would
+alter observable behavior, data model shape, or public API surface.
+The agent MUST also ask when multiple valid interpretations exist,
+when a choice would affect architectural layering, or when scope
+would expand beyond the current spec. The agent MUST NOT silently
+choose among valid alternatives.
+
+### V. Escalation Gates
+
+Any feature, requirement, or scope change not present in the current
+spec MUST be rejected at implementation time until the spec is
+explicitly updated. The workflow is:
+
+1. Identify the out-of-scope item.
+2. Document it as a proposal.
+3. Update the spec via `/speckit.specify` or `/speckit.clarify`.
+4. Only then proceed with implementation.
+
+### VI. MVP Baseline Language
+
+Constraints in this constitution and in specs MUST use MVP baseline
+language ("MVP baseline does not include X") rather than permanent
+architectural bans ("X is forbidden"). This preserves the option to
+add capabilities in future iterations without constitutional
+amendment. The current MVP baseline is local-first and single-user;
+this is a starting scope, not a permanent restriction.
+
+### VII. No Gameplay Rules in Constitution
+
+This constitution MUST NOT contain concrete gameplay mechanics,
+rule-system specifics, or encounter resolution logic. Such details
+belong in feature specs. The constitution governs process,
+architecture, and quality — not product behavior.
+
+## Scope Constraints
+
+- The Encounter Console's primary focus is initiative tracking and
+  encounter state management. Adjacent capabilities (e.g., richer
+  game-engine features) are not in the MVP baseline but may be
+  added via spec updates in future iterations.
+- Technology choices, UI framework, and storage mechanism are
+  spec-level decisions, not constitutional mandates.
+- Testing strategy (unit, integration, contract) is determined per
+  feature spec; the constitution requires only that domain logic
+  remains testable via pure-function assertions.
+
+## Development Workflow
+
+- No change may be merged unless all automated checks (tests and
+  static analysis as defined by the project) pass.
+- Every feature begins with a spec (`/speckit.specify`).
+- Implementation follows the plan → tasks → implement pipeline.
+- Domain logic MUST be testable without mocks for external systems.
+- Long-running or multi-step state transitions SHOULD be verifiable
+  through reproducible event logs or snapshot-style tests.
+- Commits SHOULD be atomic and map to individual tasks where
+  practical.
+- Layer boundary compliance MUST be verified by automated import
+  rules or architectural tests. Agent-assisted or manual review MAY
+  supplement but not replace automated checks.
 
 ## Governance
-<!-- Example: Constitution supersedes all other practices; Amendments require documentation, approval, migration plan -->
 
-[GOVERNANCE_RULES]
-<!-- Example: All PRs/reviews must verify compliance; Complexity must be justified; Use [GUIDANCE_FILE] for runtime development guidance -->
+This constitution is the highest-authority document for the
+Encounter Console project. All specs, plans, and implementations
+MUST comply with its principles.
 
-**Version**: [CONSTITUTION_VERSION] | **Ratified**: [RATIFICATION_DATE] | **Last Amended**: [LAST_AMENDED_DATE]
-<!-- Example: Version: 2.1.1 | Ratified: 2025-06-13 | Last Amended: 2025-07-16 -->
+**Amendment procedure**:
+1. Propose change with rationale.
+2. Update constitution via `/speckit.constitution`.
+3. Verify downstream template compatibility (Sync Impact Report).
+4. A human maintainer MUST review and commit the update before
+   ratification takes effect.
+5. Commit with version bump.
+
+**Versioning policy**: MAJOR.MINOR.PATCH per semantic versioning.
+- MAJOR: principle removal or backward-incompatible redefinition.
+- MINOR: new principle or materially expanded guidance.
+- PATCH: clarification, typo, or non-semantic refinement.
+
+**Compliance review**: Every spec and plan MUST include a
+Constitution Check section validating adherence to all principles.
+
+**Version**: 1.0.3 | **Ratified**: 2026-03-03 | **Last Amended**: 2026-03-03

apps/web/index.html

@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="en">
+	<head>
+		<meta charset="UTF-8" />
+		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
+		<title>Initiative Tracker</title>
+	</head>
+	<body>
+		<div id="root"></div>
+		<script type="module" src="/src/main.tsx"></script>
+	</body>
+</html>

apps/web/package.json

@@ -0,0 +1,23 @@
+{
+	"name": "web",
+	"version": "0.0.0",
+	"private": true,
+	"type": "module",
+	"scripts": {
+		"dev": "vite",
+		"build": "tsc --build && vite build",
+		"preview": "vite preview"
+	},
+	"dependencies": {
+		"@initiative/application": "workspace:*",
+		"@initiative/domain": "workspace:*",
+		"react": "^19.0.0",
+		"react-dom": "^19.0.0"
+	},
+	"devDependencies": {
+		"@types/react": "^19.0.0",
+		"@types/react-dom": "^19.0.0",
+		"@vitejs/plugin-react": "^4.3.0",
+		"vite": "^6.2.0"
+	}
+}

apps/web/src/App.tsx

@@ -0,0 +1,3 @@
+export function App() {
+	return <div>Initiative Tracker</div>;
+}

apps/web/src/main.tsx

@@ -0,0 +1,12 @@
+import { StrictMode } from "react";
+import { createRoot } from "react-dom/client";
+import { App } from "./App";
+
+const root = document.getElementById("root");
+if (root) {
+	createRoot(root).render(
+		<StrictMode>
+			<App />
+		</StrictMode>,
+	);
+}

apps/web/tsconfig.json

@@ -0,0 +1,14 @@
+{
+	"extends": "../../tsconfig.base.json",
+	"compilerOptions": {
+		"composite": true,
+		"rootDir": "src",
+		"outDir": "dist",
+		"jsx": "react-jsx"
+	},
+	"include": ["src"],
+	"references": [
+		{ "path": "../../packages/domain" },
+		{ "path": "../../packages/application" }
+	]
+}

apps/web/vite.config.ts

@@ -0,0 +1,6 @@
+import react from "@vitejs/plugin-react";
+import { defineConfig } from "vite";
+
+export default defineConfig({
+	plugins: [react()],
+});

biome.json

@@ -0,0 +1,33 @@
+{
+	"$schema": "https://biomejs.dev/schemas/2.0.0/schema.json",
+	"files": {
+		"includes": [
+			"**",
+			"!**/dist/**",
+			"!.claude/**",
+			"!.specify/**",
+			"!specs/**"
+		]
+	},
+	"assist": {
+		"enabled": true,
+		"actions": {
+			"source": {
+				"organizeImports": {
+					"level": "on"
+				}
+			}
+		}
+	},
+	"formatter": {
+		"enabled": true,
+		"indentStyle": "tab",
+		"lineWidth": 80
+	},
+	"linter": {
+		"enabled": true,
+		"rules": {
+			"recommended": true
+		}
+	}
+}

package.json

@@ -0,0 +1,19 @@
+{
+	"private": true,
+	"packageManager": "pnpm@10.6.0",
+	"devDependencies": {
+		"@biomejs/biome": "2.0.0",
+		"typescript": "^5.8.0",
+		"vitest": "^3.0.0"
+	},
+	"scripts": {
+		"format": "biome format --write .",
+		"format:check": "biome format .",
+		"lint": "biome lint .",
+		"lint:fix": "biome lint --write .",
+		"typecheck": "tsc --build",
+		"test": "vitest run",
+		"test:watch": "vitest",
+		"check": "biome check . && tsc --build && vitest run"
+	}
+}

packages/application/package.json

@@ -0,0 +1,11 @@
+{
+	"name": "@initiative/application",
+	"version": "0.0.0",
+	"private": true,
+	"type": "module",
+	"main": "./src/index.ts",
+	"types": "./src/index.ts",
+	"dependencies": {
+		"@initiative/domain": "workspace:*"
+	}
+}

packages/application/src/index.ts

@@ -0,0 +1 @@
+export {};

packages/application/tsconfig.json

@@ -0,0 +1,10 @@
+{
+	"extends": "../../tsconfig.base.json",
+	"compilerOptions": {
+		"composite": true,
+		"rootDir": "src",
+		"outDir": "dist"
+	},
+	"include": ["src"],
+	"references": [{ "path": "../domain" }]
+}

packages/domain/package.json

@@ -0,0 +1,8 @@
+{
+	"name": "@initiative/domain",
+	"version": "0.0.0",
+	"private": true,
+	"type": "module",
+	"main": "./src/index.ts",
+	"types": "./src/index.ts"
+}

packages/domain/src/__tests__/layer-boundaries.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, it } from "vitest";
+import { checkLayerBoundaries } from "../../../../scripts/check-layer-boundaries.mjs";
+
+describe("layer boundaries", () => {
+	it("domain and application packages have no forbidden imports", () => {
+		const violations = checkLayerBoundaries();
+		if (violations.length > 0) {
+			const messages = violations.map(
+				(v) =>
+					`${v.file}:${v.line} imports "${v.importPath}" (forbidden: ${v.forbidden})`,
+			);
+			throw new Error(`Layer boundary violations:\n  ${messages.join("\n  ")}`);
+		}
+		expect(violations).toHaveLength(0);
+	});
+});

packages/domain/src/index.ts

@@ -0,0 +1 @@
+export {};

packages/domain/tsconfig.json

@@ -0,0 +1,10 @@
+{
+	"extends": "../../tsconfig.base.json",
+	"compilerOptions": {
+		"composite": true,
+		"rootDir": "src",
+		"outDir": "dist"
+	},
+	"include": ["src"],
+	"exclude": ["src/__tests__"]
+}

pnpm-workspace.yaml

@@ -0,0 +1,3 @@
+packages:
+  - "packages/*"
+  - "apps/*"

scripts/check-layer-boundaries.mjs

@@ -0,0 +1,109 @@
+import { readdirSync, readFileSync } from "node:fs";
+import { join, relative } from "node:path";
+
+const ROOT = new URL("..", import.meta.url).pathname.replace(/\/$/, "");
+
+const FORBIDDEN = {
+	"packages/domain/src": [
+		"@initiative/application",
+		"apps/",
+		"react",
+		"react-dom",
+		"vite",
+	],
+	"packages/application/src": ["apps/", "react", "react-dom", "vite"],
+};
+
+/** Directories to skip when collecting files */
+const SKIP_DIRS = new Set(["__tests__", "node_modules"]);
+
+/** @param {string} dir */
+function collectTsFiles(dir) {
+	/** @type {string[]} */
+	const results = [];
+	for (const entry of readdirSync(dir, { withFileTypes: true })) {
+		const full = join(dir, entry.name);
+		if (entry.isDirectory()) {
+			if (!SKIP_DIRS.has(entry.name)) {
+				results.push(...collectTsFiles(full));
+			}
+		} else if (entry.name.endsWith(".ts") || entry.name.endsWith(".tsx")) {
+			results.push(full);
+		}
+	}
+	return results;
+}
+
+/**
+ * Check if an import path matches a forbidden module.
+ * "vite" should match "vite" and "vite/foo" but not "vitest".
+ * @param {string} importPath
+ * @param {string} forbidden
+ */
+function matchesForbidden(importPath, forbidden) {
+	if (forbidden.endsWith("/")) {
+		return importPath.startsWith(forbidden);
+	}
+	return importPath === forbidden || importPath.startsWith(`${forbidden}/`);
+}
+
+/** @returns {{ file: string, line: number, importPath: string, forbidden: string }[]} */
+export function checkLayerBoundaries() {
+	/** @type {{ file: string, line: number, importPath: string, forbidden: string }[]} */
+	const violations = [];
+
+	for (const [srcDir, forbidden] of Object.entries(FORBIDDEN)) {
+		const absDir = join(ROOT, srcDir);
+		let files;
+		try {
+			files = collectTsFiles(absDir);
+		} catch {
+			continue;
+		}
+
+		for (const file of files) {
+			const content = readFileSync(file, "utf-8");
+			const lines = content.split("\n");
+			for (let i = 0; i < lines.length; i++) {
+				const line = lines[i];
+				const match = line.match(
+					/(?:import|from)\s+["']([^"']+)["']|require\s*\(\s*["']([^"']+)["']\s*\)/,
+				);
+				if (!match) continue;
+				const importPath = match[1] || match[2];
+				for (const f of forbidden) {
+					if (matchesForbidden(importPath, f)) {
+						violations.push({
+							file: relative(ROOT, file),
+							line: i + 1,
+							importPath,
+							forbidden: f,
+						});
+					}
+				}
+			}
+		}
+	}
+
+	return violations;
+}
+
+// Run as CLI if invoked directly
+if (
+	process.argv[1] &&
+	(process.argv[1].endsWith("check-layer-boundaries.mjs") ||
+		process.argv[1] === new URL(import.meta.url).pathname)
+) {
+	const violations = checkLayerBoundaries();
+	if (violations.length > 0) {
+		console.error("Layer boundary violations found:");
+		for (const v of violations) {
+			console.error(
+				`  ${v.file}:${v.line} — imports "${v.importPath}" (forbidden: ${v.forbidden})`,
+			);
+		}
+		process.exit(1);
+	} else {
+		console.log("No layer boundary violations found.");
+	}
+}

specs/001-advance-turn/plan.md

@@ -0,0 +1,349 @@
+# Implementation Plan: Advance Turn
+
+**Branch**: `001-advance-turn` | **Date**: 2026-03-03 | **Spec**: [spec.md](./spec.md)
+**Input**: Feature specification from `/specs/001-advance-turn/spec.md`
+
+## Summary
+
+Implement the AdvanceTurn domain operation as a pure function that
+transitions an Encounter to the next combatant, wrapping rounds and
+emitting TurnAdvanced / RoundAdvanced domain events. Stand up the
+pnpm monorepo skeleton, Biome tooling, and Vitest test harness so
+that all constitution merge-gate requirements are satisfied from the
+first commit.
+
+## Technical Context
+
+**Node**: 22 LTS (pinned via `.nvmrc`)
+**Language/Version**: TypeScript 5.8 (strict mode)
+**Primary Dependencies**: React 19 (pin to major; minor upgrades
+allowed), Vite 6.2
+**Storage**: In-memory only (MVP baseline)
+**Testing**: Vitest 3.0
+**Lint/Format**: Biome 2.0.0 (exact version, single tool — no
+Prettier, no ESLint)
+**Package Manager**: pnpm 10.6 (pinned via `packageManager` field
+in root `package.json`)
+**Target Platform**: Static web app (modern browsers)
+**Project Type**: Monorepo — library packages + web app
+**Performance Goals**: N/A (walking skeleton)
+**Constraints**: Domain package must have zero React/Vite imports
+**Scale/Scope**: Single feature, ~5 source files, ~1 test file
+
+## Constitution Check
+
+| Principle | Status | Notes |
+|-----------|--------|-------|
+| I. Deterministic Domain Core | PASS | `advanceTurn` is a pure function; no I/O, randomness, or clocks |
+| II. Layered Architecture | PASS | `packages/domain` → `packages/application` → `apps/web`; strict dependency direction enforced by automated import check |
+| III. Agent Boundary | N/A | Agent layer out of scope for this feature |
+| IV. Clarification-First | PASS | No ambiguous decisions remain; spec fully clarified |
+| V. Escalation Gates | PASS | Scope strictly limited to spec; out-of-scope items listed |
+| VI. MVP Baseline Language | PASS | No permanent bans; "MVP baseline does not include" used |
+| VII. No Gameplay Rules | PASS | No gameplay mechanics in plan or constitution |
+| Merge Gate | PASS | `pnpm check` script runs format, lint, typecheck, test |
+
+## Project Structure
+
+### Documentation (this feature)
+
+```text
+specs/001-advance-turn/
+├── spec.md
+└── plan.md
+```
+
+### Source Code (repository root)
+
+```text
+packages/
+├── domain/
+│   ├── package.json
+│   ├── tsconfig.json
+│   └── src/
+│       ├── types.ts          # CombatantId, Combatant, Encounter
+│       ├── events.ts         # TurnAdvanced, RoundAdvanced, DomainEvent
+│       ├── advance-turn.ts   # advanceTurn pure function
+│       └── index.ts          # public barrel export
+├── application/
+│   ├── package.json
+│   ├── tsconfig.json
+│   └── src/
+│       ├── ports.ts          # EncounterStore port interface
+│       ├── advance-turn-use-case.ts
+│       └── index.ts
+apps/
+└── web/
+    ├── package.json
+    ├── tsconfig.json
+    ├── vite.config.ts
+    ├── index.html
+    └── src/
+        ├── main.tsx
+        ├── App.tsx
+        └── hooks/
+            └── use-encounter.ts
+
+# Testing (co-located with domain package)
+packages/domain/
+└── src/
+    └── __tests__/
+        └── advance-turn.test.ts
+
+# Root config
+├── .nvmrc                    # pins Node 22
+├── pnpm-workspace.yaml
+├── biome.json
+├── tsconfig.base.json
+└── package.json              # packageManager field pins pnpm; root scripts
+```
+
+**Structure Decision**: pnpm workspace monorepo with two packages
+(`domain`, `application`) and one app (`web`). Domain is
+framework-agnostic TypeScript. Application imports domain only.
+Web app (React + Vite) imports both.
+
+## Tooling & Merge Gate
+
+### Scripts (root package.json)
+
+```jsonc
+{
+  "scripts": {
+    "format": "biome format --write .",
+    "format:check": "biome format .",
+    "lint": "biome lint .",
+    "lint:fix": "biome lint --write .",
+    "typecheck": "tsc --build",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "check": "biome check . && tsc --build && vitest run"
+  }
+}
+```
+
+`pnpm check` is the single merge gate: format + lint + typecheck +
+test. The layer boundary check runs as a Vitest test (see below),
+so it executes as part of `vitest run` — no separate script needed.
+
+### Layer Boundary Enforcement
+
+Biome does not natively support cross-package import restrictions.
+A lightweight `scripts/check-layer-boundaries.mjs` script will:
+
+1. Scan `packages/domain/src/**/*.ts` — assert zero imports from
+   `@initiative/application`, `apps/`, `react`, `vite`.
+2. Scan `packages/application/src/**/*.ts` — assert zero imports
+   from `apps/`, `react`, `vite`.
+3. Exit non-zero on violation with a clear error message.
+
+This script is invoked by a Vitest test
+(`packages/domain/src/__tests__/layer-boundaries.test.ts`) so it
+runs automatically as part of `vitest run` inside `pnpm check`.
+No separate `check:layer` script is needed — the layer boundary
+check is guaranteed to execute on every merge-gate run.
+
+### Biome Configuration (biome.json)
+
+```jsonc
+{
+  "$schema": "https://biomejs.dev/schemas/2.0.0/schema.json",
+  "organizeImports": { "enabled": true },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "tab",
+    "lineWidth": 80
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true
+    }
+  }
+}
+```
+
+### TypeScript Configuration
+
+- `tsconfig.base.json` at root: strict mode, composite projects,
+  path aliases (`@initiative/domain`, `@initiative/application`).
+- Each package extends `tsconfig.base.json` with its own
+  `include`/`references`.
+- `apps/web/tsconfig.json` references both packages.
+
+## Milestones
+
+### Milestone 1: Tooling & Domain (walking skeleton)
+
+Stand up monorepo, Biome, Vitest, TypeScript project references,
+and implement the complete AdvanceTurn domain logic with all tests.
+
+**Exit criteria**: `pnpm check` passes. All 8 acceptance scenarios
+green. Layer boundary check green. No React or Vite dependencies in
+`packages/domain` or `packages/application`.
+
+### Milestone 2: Application + Minimal Web Shell
+
+Wire up the application use case and a minimal React UI that
+displays the encounter state and has a single "Next Turn" button.
+
+**Exit criteria**: `pnpm check` passes. Clicking "Next Turn" in the
+browser advances the turn with correct round wrapping. The app
+builds with `vite build`.
+
+## Task List
+
+### Phase 1: Setup (Milestone 1)
+
+- [X] **T001** Initialize pnpm workspace and root config
+  - Create `pnpm-workspace.yaml` listing `packages/*` and `apps/*`
+  - Create `.nvmrc` pinning Node 22
+  - Create root `package.json` with `packageManager` field pinning
+    pnpm 10.6 and scripts (check, test, lint, format, typecheck)
+  - Create `biome.json` at root
+  - Create `tsconfig.base.json` (strict, composite, path aliases)
+  - **Acceptance**: `pnpm install` succeeds; `biome check .` runs
+    without config errors
+
+- [X] **T002** [P] Create `packages/domain` package skeleton
+  - `package.json` (name: `@initiative/domain`, no dependencies)
+  - `tsconfig.json` extending base, composite: true
+  - Empty `src/index.ts`
+  - **Acceptance**: `tsc --build packages/domain` succeeds
+
+- [X] **T003** [P] Create `packages/application` package skeleton
+  - `package.json` (name: `@initiative/application`,
+    depends on `@initiative/domain`)
+  - `tsconfig.json` extending base, references domain
+  - Empty `src/index.ts`
+  - **Acceptance**: `tsc --build packages/application` succeeds
+
+- [X] **T004** [P] Create `apps/web` package skeleton
+  - `package.json` with React, Vite, depends on both packages
+  - `tsconfig.json` referencing both packages
+  - `vite.config.ts` (minimal)
+  - `index.html` + `src/main.tsx` + `src/App.tsx` (placeholder)
+  - **Acceptance**: `pnpm --filter web dev` starts; `vite build`
+    succeeds
+
+- [X] **T005** Configure Vitest
+  - Add `vitest` as root dev dependency
+  - Create `vitest.config.ts` at root (workspace mode) or per
+    package as needed
+  - Verify `pnpm test` runs (0 tests, exits clean)
+  - **Acceptance**: `pnpm test` exits 0
+
+- [X] **T006** Create layer boundary check script
+  - `scripts/check-layer-boundaries.mjs`: scans domain and
+    application source for forbidden imports
+  - `packages/domain/src/__tests__/layer-boundaries.test.ts`:
+    wraps the script as a Vitest test
+  - **Acceptance**: test passes on clean skeleton; fails if a
+    forbidden import is manually added (verify, then remove)
+
+### Phase 2: Domain Implementation (Milestone 1)
+
+- [ ] **T007** Define domain types in `packages/domain/src/types.ts`
+  - `CombatantId` (branded string or opaque type)
+  - `Combatant` (carries a CombatantId)
+  - `Encounter` (combatants array, activeIndex, roundNumber)
+  - Factory function `createEncounter` that validates INV-1, INV-2,
+    INV-3
+  - **Acceptance**: types compile; `createEncounter([])` returns
+    error; `createEncounter([a])` returns valid Encounter
+
+- [ ] **T008** [P] Define domain events in
+  `packages/domain/src/events.ts`
+  - `TurnAdvanced { previousCombatantId, newCombatantId,
+    roundNumber }`
+  - `RoundAdvanced { newRoundNumber }`
+  - `DomainEvent = TurnAdvanced | RoundAdvanced`
+  - **Acceptance**: types compile; events are plain data (no
+    classes with methods)
+
+- [ ] **T009** Implement `advanceTurn` in
+  `packages/domain/src/advance-turn.ts`
+  - Signature: `(encounter: Encounter) =>
+    { encounter: Encounter; events: DomainEvent[] } | DomainError`
+  - Implements FR-001 through FR-005
+  - Returns error for empty combatant list (INV-1)
+  - Emits TurnAdvanced on every call (INV-5)
+  - Emits TurnAdvanced then RoundAdvanced on wrap (event order
+    contract)
+  - **Acceptance**: compiles; satisfies type contract
+
+- [ ] **T010** Write tests for all 8 acceptance scenarios +
+  invariants in
+  `packages/domain/src/__tests__/advance-turn.test.ts`
+  - Scenarios 1–8 from spec (Given/When/Then)
+  - INV-1: empty encounter rejected
+  - INV-2: activeIndex always in bounds (property check across
+    scenarios)
+  - INV-3: roundNumber never decreases
+  - INV-4: determinism — same input produces same output (call
+    twice, assert deep equal)
+  - INV-5: every success emits at least TurnAdvanced
+  - Event ordering: on wrap, events array is
+    [TurnAdvanced, RoundAdvanced] in that order
+  - **Acceptance**: `pnpm test` — all tests green; `pnpm check` —
+    full pipeline green
+
+- [ ] **T011** Export public API from `packages/domain/src/index.ts`
+  - Re-export types, events, `advanceTurn`, `createEncounter`
+  - **Acceptance**: consuming packages can
+    `import { advanceTurn } from "@initiative/domain"`
+
+**Milestone 1 checkpoint**: `pnpm check` passes (format + lint +
+typecheck + test + layer boundaries). All 8 scenarios + invariants
+green.
+
+### Phase 3: Application + Web Shell (Milestone 2)
+
+- [ ] **T012** Define port interface in
+  `packages/application/src/ports.ts`
+  - `EncounterStore` port: `get(): Encounter`, `save(e: Encounter)`
+  - **Acceptance**: compiles; no imports from adapters or React
+
+- [ ] **T013** Implement `AdvanceTurnUseCase` in
+  `packages/application/src/advance-turn-use-case.ts`
+  - Accepts `EncounterStore` port
+  - Calls `advanceTurn` from domain, saves result, returns events
+  - **Acceptance**: compiles; imports only from `@initiative/domain`
+    and local ports
+
+- [ ] **T014** Export public API from
+  `packages/application/src/index.ts`
+  - Re-export use case and port types
+  - **Acceptance**: consuming app can import from
+    `@initiative/application`
+
+- [ ] **T015** Implement `useEncounter` hook in
+  `apps/web/src/hooks/use-encounter.ts`
+  - In-memory implementation of `EncounterStore` port (React state)
+  - Exposes current encounter state + `advanceTurn` action
+  - Initializes with a hardcoded 3-combatant encounter for demo
+  - **Acceptance**: hook compiles; usable in a React component
+
+- [ ] **T016** Wire up `App.tsx`
+  - Display: current combatant name, round number, combatant list
+    with active indicator
+  - Single "Next Turn" button calling the use case
+  - Display emitted events (optional, for demo clarity)
+  - **Acceptance**: `vite build` succeeds; clicking "Next Turn"
+    cycles through combatants and increments rounds correctly
+
+**Milestone 2 checkpoint**: `pnpm check` passes. App runs in
+browser. Full round-trip from button click → domain pure function →
+UI update verified manually.
+
+## Risks & Open Questions
+
+| # | Item | Severity | Mitigation |
+|---|------|----------|------------|
+| 1 | pnpm workspace + TypeScript project references can have path resolution quirks with Vite | Low | Use `vite-tsconfig-paths` plugin if needed; test early in T004 |
+| 2 | Biome config format may change across versions | Low | Pinned to exact 2.0.0; `$schema` in config validates structure |
+| 3 | Layer boundary script is a lightweight grep — not a full architectural fitness function | Low | Sufficient for walking skeleton; can upgrade to a Biome plugin or `dependency-cruiser` later if needed |
+
+## Complexity Tracking
+
+No constitution violations. No complexity justifications needed.

specs/001-advance-turn/spec.md

@@ -0,0 +1,160 @@
+# Feature Specification: Advance Turn
+
+**Feature Branch**: `001-advance-turn`
+**Created**: 2026-03-03
+**Status**: Draft
+**Input**: Walking-skeleton domain feature — deterministic turn advancement
+
+## User Scenarios & Testing *(mandatory)*
+
+### User Story 1 - Advance Turn (Priority: P1)
+
+A game master running an encounter advances the turn to the next
+combatant in initiative order. When the last combatant in the round
+finishes, the round number increments and play wraps to the first
+combatant.
+
+**Why this priority**: This is the irreducible core of an initiative
+tracker. Without turn advancement, no other feature has meaning.
+
+**Independent Test**: Can be fully tested as a pure state transition
+with no I/O, persistence, or UI. Given an Encounter value and an
+AdvanceTurn action, assert the resulting Encounter value and emitted
+domain events.
+
+**Acceptance Scenarios**:
+
+1. **Given** an encounter with combatants [A, B, C], activeIndex 0,
+   roundNumber 1,
+   **When** AdvanceTurn,
+   **Then** activeIndex is 1, roundNumber is 1,
+   and a TurnAdvanced event is emitted with
+   previousCombatantId A, newCombatantId B, roundNumber 1.
+
+2. **Given** an encounter with combatants [A, B, C], activeIndex 1,
+   roundNumber 1,
+   **When** AdvanceTurn,
+   **Then** activeIndex is 2, roundNumber is 1,
+   and a TurnAdvanced event is emitted with
+   previousCombatantId B, newCombatantId C, roundNumber 1.
+
+3. **Given** an encounter with combatants [A, B, C], activeIndex 2,
+   roundNumber 1,
+   **When** AdvanceTurn,
+   **Then** activeIndex is 0, roundNumber is 2,
+   and events are emitted in order: TurnAdvanced
+   (previousCombatantId C, newCombatantId A, roundNumber 2) then
+   RoundAdvanced (newRoundNumber 2).
+
+4. **Given** an encounter with combatants [A, B, C], activeIndex 2,
+   roundNumber 5,
+   **When** AdvanceTurn,
+   **Then** activeIndex is 0, roundNumber is 6,
+   and events are emitted in order: TurnAdvanced then RoundAdvanced
+   (verifies round increment is not hardcoded to 2).
+
+5. **Given** an encounter with a single combatant [A], activeIndex 0,
+   roundNumber 1,
+   **When** AdvanceTurn,
+   **Then** activeIndex is 0, roundNumber is 2,
+   and events are emitted in order: TurnAdvanced
+   (previousCombatantId A, newCombatantId A, roundNumber 2) then
+   RoundAdvanced (newRoundNumber 2).
+
+6. **Given** an encounter with combatants [A, B], activeIndex 0,
+   roundNumber 1,
+   **When** AdvanceTurn is applied twice in sequence,
+   **Then** after the first: activeIndex 1, roundNumber 1;
+   after the second: activeIndex 0, roundNumber 2.
+
+7. **Given** an encounter with an empty combatant list,
+   **When** AdvanceTurn,
+   **Then** the operation MUST fail with an invalid-encounter error.
+   No events are emitted. State is unchanged.
+
+8. **Given** an encounter with combatants [A, B, C], activeIndex 0,
+   roundNumber 1,
+   **When** AdvanceTurn is applied three times,
+   **Then** the encounter completes a full round cycle:
+   activeIndex returns to 0 and roundNumber is 2.
+
+---
+
+### Edge Cases
+
+- Empty combatant list: AdvanceTurn MUST reject with an error.
+- Single combatant: every advance wraps and increments the round.
+- Large round numbers: no overflow or special-case behavior; round
+  increments uniformly.
+
+## Domain Model *(mandatory)*
+
+### Key Entities
+
+- **Combatant**: An identified participant in the encounter. For this
+  feature, a combatant is an opaque identity (e.g., a name or id).
+  The MVP baseline does not include HP, conditions, or stats.
+- **Encounter**: The aggregate root. Contains an ordered list of
+  combatants (pre-sorted by initiative), an activeIndex pointing to
+  the current combatant, and a roundNumber (positive integer,
+  starting at 1).
+
+### Domain Events
+
+- **TurnAdvanced**: Emitted on every successful AdvanceTurn.
+  Carries: previousCombatantId, newCombatantId, roundNumber.
+- **RoundAdvanced**: Emitted when activeIndex wraps past the last
+  combatant. Carries: newRoundNumber.
+
+When a round boundary is crossed, both TurnAdvanced and
+RoundAdvanced MUST be emitted in that order (TurnAdvanced first).
+This emission order is part of the observable domain contract and
+MUST be verified by tests.
+
+### Invariants
+
+- **INV-1**: An encounter MUST have at least one combatant.
+  Operations on an empty encounter MUST fail.
+- **INV-2**: activeIndex MUST always satisfy
+  0 <= activeIndex < len(combatants).
+- **INV-3**: roundNumber MUST be a positive integer (>= 1) and MUST
+  only increase (never decrease or reset).
+- **INV-4**: AdvanceTurn MUST be a pure function of the current
+  encounter state. Given identical input, output MUST be identical.
+- **INV-5**: Every successful AdvanceTurn MUST emit at least one
+  domain event (TurnAdvanced). No silent state changes.
+
+## Requirements *(mandatory)*
+
+### Functional Requirements
+
+- **FR-001**: The domain MUST expose an AdvanceTurn operation that
+  accepts an Encounter and returns the next Encounter state plus
+  emitted domain events.
+- **FR-002**: AdvanceTurn MUST increment activeIndex by 1, wrapping
+  to 0 when past the last combatant.
+- **FR-003**: When activeIndex wraps to 0, roundNumber MUST
+  increment by 1.
+- **FR-004**: AdvanceTurn on an empty encounter MUST return an error
+  without modifying state or emitting events.
+- **FR-005**: Domain events MUST be returned as values from the
+  operation, not dispatched via side effects.
+
+### Out of Scope (MVP baseline does not include)
+
+- Initiative rolling or combatant ordering logic
+- Hit points, damage, conditions, or status effects
+- Adding or removing combatants mid-encounter
+- Persistence, serialization, or storage
+- UI, CLI, or any adapter layer
+- Agent behavior or suggestions
+
+## Success Criteria *(mandatory)*
+
+### Measurable Outcomes
+
+- **SC-001**: All 8 acceptance scenarios pass as deterministic,
+  pure-function tests with no I/O dependencies.
+- **SC-002**: Invariants INV-1 through INV-5 are verified by tests.
+- **SC-003**: The domain module has zero imports from application,
+  adapter, or agent layers (layer boundary compliance).

specs/001-advance-turn/tasks.md

@@ -0,0 +1,128 @@
+# Tasks: Advance Turn
+
+**Input**: Design documents from `/specs/001-advance-turn/`
+**Prerequisites**: plan.md (required), spec.md (required)
+
+**Organization**: Tasks follow the phased structure from plan.md. There is only one user story (US1 — Advance Turn, P1), so phases map directly to the plan's milestones.
+
+## Format: `[ID] [P?] [Story?] Description`
+
+- **[P]**: Can run in parallel (different files, no dependencies)
+- **[US1]**: User Story 1 — Advance Turn
+- Exact file paths included in every task
+
+---
+
+## Phase 1: Setup (Milestone 1 — Tooling)
+
+**Purpose**: Initialize pnpm monorepo, Biome, TypeScript, Vitest, and layer boundary enforcement
+
+- [X] T001 Initialize pnpm workspace and root config — create `pnpm-workspace.yaml`, `.nvmrc` (Node 22), root `package.json` (with `packageManager` pinning pnpm 10.6 and scripts: check, test, lint, format, typecheck), `biome.json`, and `tsconfig.base.json` (strict, composite, path aliases)
+- [X] T002 [P] Create `packages/domain` package skeleton — `packages/domain/package.json` (`@initiative/domain`, no deps), `packages/domain/tsconfig.json` (extends base, composite), empty `packages/domain/src/index.ts`
+- [X] T003 [P] Create `packages/application` package skeleton — `packages/application/package.json` (`@initiative/application`, depends on `@initiative/domain`), `packages/application/tsconfig.json` (extends base, references domain), empty `packages/application/src/index.ts`
+- [X] T004 [P] Create `apps/web` package skeleton — `apps/web/package.json` (React 19, Vite 6.2, depends on both packages), `apps/web/tsconfig.json`, `apps/web/vite.config.ts`, `apps/web/index.html`, `apps/web/src/main.tsx`, `apps/web/src/App.tsx` (placeholder)
+- [X] T005 Configure Vitest — add `vitest` as root dev dependency, create `vitest.config.ts` at root (workspace mode or per-package), verify `pnpm test` exits 0
+- [X] T006 Create layer boundary check — `scripts/check-layer-boundaries.mjs` (scans domain/application for forbidden imports) and `packages/domain/src/__tests__/layer-boundaries.test.ts` (wraps script as Vitest test)
+
+**Checkpoint**: `pnpm install` succeeds, `biome check .` runs, `tsc --build` compiles, `pnpm test` exits 0 with layer boundary test green.
+
+---
+
+## Phase 2: Domain Implementation — User Story 1: Advance Turn (Priority: P1) (Milestone 1)
+
+**Goal**: Implement the complete AdvanceTurn domain logic as a pure function with all 8 acceptance scenarios and invariant tests.
+
+**Independent Test**: Pure state transition — given an Encounter value and AdvanceTurn action, assert resulting Encounter and emitted domain events. No I/O, persistence, or UI needed.
+
+- [ ] T007 [US1] Define domain types in `packages/domain/src/types.ts` — `CombatantId` (branded/opaque), `Combatant`, `Encounter` (combatants, activeIndex, roundNumber), factory `createEncounter` enforcing INV-1, INV-2, INV-3
+- [ ] T008 [P] [US1] Define domain events in `packages/domain/src/events.ts` — `TurnAdvanced`, `RoundAdvanced`, `DomainEvent` union (plain data, no classes)
+- [ ] T009 [US1] Implement `advanceTurn` in `packages/domain/src/advance-turn.ts` — pure function `(Encounter) => { encounter, events } | DomainError`, implements FR-001 through FR-005
+- [ ] T010 [US1] Write tests for all 8 acceptance scenarios + invariants in `packages/domain/src/__tests__/advance-turn.test.ts` — scenarios 1–8, INV-1 through INV-5, event ordering on round wrap
+- [ ] T011 [US1] Export public API from `packages/domain/src/index.ts` — re-export types, events, `advanceTurn`, `createEncounter`
+
+**Checkpoint (Milestone 1)**: `pnpm check` passes (format + lint + typecheck + test + layer boundaries). All 8 scenarios + invariants green. No React/Vite imports in domain or application.
+
+---
+
+## Phase 3: Application + Web Shell (Milestone 2)
+
+**Goal**: Wire up the application use case and minimal React UI with a "Next Turn" button.
+
+- [ ] T012 Define port interface in `packages/application/src/ports.ts` — `EncounterStore` port: `get(): Encounter`, `save(e: Encounter)`
+- [ ] T013 Implement `AdvanceTurnUseCase` in `packages/application/src/advance-turn-use-case.ts` — accepts `EncounterStore`, calls `advanceTurn`, saves result, returns events
+- [ ] T014 Export public API from `packages/application/src/index.ts` — re-export use case and port types
+- [ ] T015 Implement `useEncounter` hook in `apps/web/src/hooks/use-encounter.ts` — in-memory `EncounterStore` via React state, exposes encounter state + `advanceTurn` action, hardcoded 3-combatant demo
+- [ ] T016 Wire up `apps/web/src/App.tsx` — display current combatant, round number, combatant list with active indicator, "Next Turn" button, emitted events
+
+**Checkpoint (Milestone 2)**: `pnpm check` passes. `vite build` succeeds. Clicking "Next Turn" cycles combatants and increments rounds correctly.
+
+---
+
+## Dependencies & Execution Order
+
+### Phase Dependencies
+
+- **Phase 1 (Setup)**: No dependencies — start immediately
+- **Phase 2 (Domain)**: Depends on Phase 1 completion
+- **Phase 3 (App + Web)**: Depends on Phase 2 completion (needs domain types and `advanceTurn`)
+
+### Within Phase 1
+
+- T001 must complete first (workspace and root config)
+- T002, T003, T004 can run in parallel [P] after T001
+- T005 depends on T001 (needs root package.json)
+- T006 depends on T002 and T005 (needs domain package + Vitest)
+
+### Within Phase 2
+
+- T007 must complete first (types needed by everything)
+- T008 can run in parallel [P] with T007 (events are independent types)
+- T009 depends on T007 and T008 (uses types and events)
+- T010 depends on T009 (tests the implementation)
+- T011 depends on T007, T008, T009 (exports all public API)
+
+### Within Phase 3
+
+- T012 first (port interface)
+- T013 depends on T012 (uses port)
+- T014 depends on T013 (exports use case)
+- T015 depends on T014 (uses application layer)
+- T016 depends on T015 (uses hook)
+
+---
+
+## Parallel Opportunities
+
+```text
+# After T001 completes:
+T002, T003, T004 — all package skeletons in parallel
+
+# After T007 starts:
+T008 — domain events can be written in parallel with types
+
+# Independent stories: only one user story (US1), so parallelism is within-phase only
+```
+
+---
+
+## Implementation Strategy
+
+### MVP First (Milestone 1)
+
+1. Complete Phase 1: Setup (T001–T006)
+2. Complete Phase 2: Domain (T007–T011)
+3. **STOP and VALIDATE**: `pnpm check` passes, all 8 scenarios green
+
+### Full Feature (Milestone 2)
+
+4. Complete Phase 3: App + Web Shell (T012–T016)
+5. **VALIDATE**: `pnpm check` passes, app runs in browser
+
+---
+
+## Notes
+
+- All task IDs (T001–T016) match plan.md — no scope expansion
+- Single user story (US1: Advance Turn) — no cross-story dependencies
+- Tests (T010) are included as specified in plan.md and spec.md
+- Domain package must have zero React/Vite imports (enforced by T006)

tsconfig.base.json

@@ -0,0 +1,17 @@
+{
+	"compilerOptions": {
+		"strict": true,
+		"target": "ES2022",
+		"module": "ESNext",
+		"moduleResolution": "bundler",
+		"declaration": true,
+		"declarationMap": true,
+		"sourceMap": true,
+		"composite": true,
+		"esModuleInterop": true,
+		"skipLibCheck": true,
+		"forceConsistentCasingInFileNames": true,
+		"isolatedModules": true,
+		"verbatimModuleSyntax": true
+	}
+}

tsconfig.json

@@ -0,0 +1,8 @@
+{
+	"files": [],
+	"references": [
+		{ "path": "packages/domain" },
+		{ "path": "packages/application" },
+		{ "path": "apps/web" }
+	]
+}

vitest.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+	test: {
+		include: ["packages/*/src/**/*.test.ts"],
+		passWithNoTests: true,
+	},
+});