feat(setup/project-init): initialize TypeScript ESM project skeleton

- package.json with @alkdev/taskgraph, ESM primary, CJS compat exports
- tsconfig.json targeting Node 18+, strict mode, declaration output
- All production deps: graphology suite, @alkdev/typebox, yaml
- Dev deps: typescript, vitest, @types/node
- src/ skeleton: schema, graph, analysis, frontmatter, error modules
- test/ directory with 5 placeholder test files
- .gitignore and vitest.config.ts

src/analysis/bottleneck.ts

@@ -0,0 +1 @@
+// bottlenecks (graphology betweenness)

src/analysis/cost-benefit.ts

@@ -0,0 +1 @@
+// calculateTaskEv, workflowCost, computeEffectiveP

src/analysis/critical-path.ts

@@ -0,0 +1 @@
+// criticalPath, weightedCriticalPath

src/analysis/decompose.ts

@@ -0,0 +1 @@
+// shouldDecomposeTask

src/analysis/defaults.ts

@@ -0,0 +1 @@
+// resolveDefaults, enum numeric methods

src/analysis/index.ts

@@ -0,0 +1,8 @@
+// Analysis submodule — re-exports
+
+export * from './critical-path.js';
+export * from './bottleneck.js';
+export * from './risk.js';
+export * from './cost-benefit.js';
+export * from './decompose.js';
+export * from './defaults.js';

src/analysis/risk.ts

@@ -0,0 +1 @@
+// riskPath, riskDistribution

src/error/index.ts

@@ -0,0 +1,44 @@
+// Error classes — TaskgraphError, TaskNotFoundError, CircularDependencyError,
+// InvalidInputError, DuplicateNodeError, DuplicateEdgeError
+
+export class TaskgraphError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'TaskgraphError';
+  }
+}
+
+export class TaskNotFoundError extends TaskgraphError {
+  constructor(taskId: string) {
+    super(`Task not found: ${taskId}`);
+    this.name = 'TaskNotFoundError';
+  }
+}
+
+export class CircularDependencyError extends TaskgraphError {
+  constructor(cycle: string[]) {
+    super(`Circular dependency detected: ${cycle.join(' → ')}`);
+    this.name = 'CircularDependencyError';
+  }
+}
+
+export class InvalidInputError extends TaskgraphError {
+  constructor(message: string) {
+    super(message);
+    this.name = 'InvalidInputError';
+  }
+}
+
+export class DuplicateNodeError extends TaskgraphError {
+  constructor(nodeId: string) {
+    super(`Duplicate node: ${nodeId}`);
+    this.name = 'DuplicateNodeError';
+  }
+}
+
+export class DuplicateEdgeError extends TaskgraphError {
+  constructor(source: string, target: string) {
+    super(`Duplicate edge: ${source} → ${target}`);
+    this.name = 'DuplicateEdgeError';
+  }
+}

src/frontmatter/index.ts

@@ -0,0 +1,4 @@
+// Frontmatter submodule — parse and serialize
+
+export { parseFrontmatter, parseTaskFile, parseTaskDirectory } from './parse.js';
+export { serializeFrontmatter } from './serialize.js';

src/frontmatter/parse.ts

@@ -0,0 +1,16 @@
+// YAML/frontmatter parsing + typebox validation
+
+export function parseFrontmatter(_input: string): unknown {
+  // Stub — implementation pending
+  return {};
+}
+
+export function parseTaskFile(_input: string): unknown {
+  // Stub — implementation pending
+  return {};
+}
+
+export function parseTaskDirectory(_dir: string): unknown[] {
+  // Stub — implementation pending
+  return [];
+}

src/frontmatter/serialize.ts

@@ -0,0 +1,6 @@
+// TaskInput → markdown with frontmatter
+
+export function serializeFrontmatter(_input: unknown): string {
+  // Stub — implementation pending
+  return '';
+}

src/graph/construction.ts

@@ -0,0 +1,5 @@
+// TaskGraph class construction — fromTasks, fromRecords, fromJSON, incremental building
+
+export class TaskGraph {
+  // Stub — implementation pending
+}

src/graph/index.ts

@@ -0,0 +1,5 @@
+// Graph submodule — TaskGraph class and operations
+
+export { TaskGraph } from './construction.js';
+export * from './queries.js';
+export * from './mutation.js';

src/graph/mutation.ts

@@ -0,0 +1 @@
+// Graph mutations — removeTask, removeDependency, updateTask, updateEdgeAttributes

src/graph/queries.ts

@@ -0,0 +1 @@
+// Graph queries — hasCycles, findCycles, topologicalOrder, dependencies, dependents

src/index.ts

@@ -0,0 +1,8 @@
+// @alkdev/taskgraph — Public API surface
+// Re-exports from all submodules
+
+export * from './schema/index.js';
+export * from './graph/index.js';
+export * from './analysis/index.js';
+export * from './frontmatter/index.js';
+export * from './error/index.js';

src/schema/enums.ts

@@ -0,0 +1 @@
+// Enum definitions: TaskScope, TaskRisk, TaskImpact, TaskLevel, TaskStatus, TaskPriority

src/schema/graph.ts

@@ -0,0 +1 @@
+// TaskGraphNodeAttributes, TaskGraphEdgeAttributes, SerializedGraph schemas

src/schema/index.ts

@@ -0,0 +1,6 @@
+// Schema submodule — re-exports
+
+export * from './enums.js';
+export * from './task.js';
+export * from './graph.js';
+export * from './results.js';

src/schema/results.ts

@@ -0,0 +1 @@
+// RiskPathResult, DecomposeResult, WorkflowCostResult, RiskDistributionResult schemas

src/schema/task.ts

@@ -0,0 +1 @@
+// TaskInput, DependencyEdge schemas