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

test/analysis.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('Analysis', () => {
+  it('placeholder — critical path and risk analysis', () => {
+    expect(true).toBe(true);
+  });
+});

test/cost-benefit.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('Cost-Benefit', () => {
+  it('placeholder — EV and workflow cost calculations', () => {
+    expect(true).toBe(true);
+  });
+});

test/frontmatter.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('Frontmatter', () => {
+  it('placeholder — parse and serialize', () => {
+    expect(true).toBe(true);
+  });
+});

test/graph.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('TaskGraph', () => {
+  it('placeholder — construction and queries', () => {
+    expect(true).toBe(true);
+  });
+});

test/schema.test.ts

@@ -0,0 +1,7 @@
+import { describe, it, expect } from 'vitest';
+
+describe('Schema', () => {
+  it('placeholder — schema validation', () => {
+    expect(true).toBe(true);
+  });
+});