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

tasks/implementation/setup/project-init.md

@@ -1,7 +1,7 @@
 ---
 id: setup/project-init
 name: Initialize project with package.json, tsconfig, and build tooling
-status: pending
+status: completed
 depends_on: []
 scope: moderate
 risk: low
@@ -22,21 +22,21 @@ Per [build-distribution.md](../../../docs/architecture/build-distribution.md):
 
 ## Acceptance Criteria
 
-- [ ] `package.json` exists with name `@alkdev/taskgraph`, ESM primary (`"type": "module"`), CJS compat config
-- [ ] All production dependencies listed per [build-distribution.md](../../../docs/architecture/build-distribution.md) dependencies table
-- [ ] Dev dependencies include: `typescript`, `vitest` (or agreed test runner), `@types/node`
-- [ ] `tsconfig.json` configured for Node 18+ target, ESM module resolution, strict mode, declaration output
-- [ ] `.gitignore` covers `node_modules/`, `dist/`, `*.js.map`, `.env`
-- [ ] `src/` directory skeleton created per [build-distribution.md](../../../docs/architecture/build-distribution.md) project structure:
+- [x] `package.json` exists with name `@alkdev/taskgraph`, ESM primary (`"type": "module"`), CJS compat config
+- [x] All production dependencies listed per [build-distribution.md](../../../docs/architecture/build-distribution.md) dependencies table
+- [x] Dev dependencies include: `typescript`, `vitest` (or agreed test runner), `@types/node`
+- [x] `tsconfig.json` configured for Node 18+ target, ESM module resolution, strict mode, declaration output
+- [x] `.gitignore` covers `node_modules/`, `dist/`, `*.js.map`, `.env`
+- [x] `src/` directory skeleton created per [build-distribution.md](../../../docs/architecture/build-distribution.md) project structure:
   - `src/index.ts`
   - `src/schema/index.ts`, `src/schema/enums.ts`, `src/schema/task.ts`, `src/schema/graph.ts`, `src/schema/results.ts`
   - `src/graph/index.ts`, `src/graph/construction.ts`, `src/graph/queries.ts`, `src/graph/mutation.ts`
   - `src/analysis/index.ts`, `src/analysis/critical-path.ts`, `src/analysis/bottleneck.ts`, `src/analysis/risk.ts`, `src/analysis/cost-benefit.ts`, `src/analysis/decompose.ts`, `src/analysis/defaults.ts`
   - `src/frontmatter/index.ts`, `src/frontmatter/parse.ts`, `src/frontmatter/serialize.ts`
   - `src/error/index.ts`
-- [ ] `test/` directory created with placeholder test files per build-distribution spec
-- [ ] `npm install` succeeds without errors
-- [ ] `npx tsc --noEmit` succeeds (empty source files, but config is valid)
+- [x] `test/` directory created with placeholder test files per build-distribution spec
+- [x] `npm install` succeeds without errors
+- [x] `npx tsc --noEmit` succeeds (empty source files, but config is valid)
 
 ## References
 
@@ -44,8 +44,20 @@ Per [build-distribution.md](../../../docs/architecture/build-distribution.md):
 
 ## Notes
 
-> To be filled by implementation agent
+Dependency version adjustments from architecture spec:
+- `@alkdev/typebox`: ^0.2.0 → ^0.34.49 (only version available on npm)
+- `graphology`: ^0.25.4 → ^0.26.0 (latest on npm)
+- `graphology-dag`: ^0.4.2 → ^0.4.1 (latest on npm)
+- `graphology-metrics`: ^0.7.0 → ^2.4.0 (latest on npm)
+- `graphology-components`: ^0.3.1 → ^1.5.4 (latest on npm)
+- `graphology-operators`: ^0.5.2 → ^1.6.1 (latest on npm)
+- `yaml`: ^2.6.1 → ^2.8.3 (latest on npm)
 
 ## Summary
 
-> To be filled on completion
+Initialized the @alkdev/taskgraph TypeScript ESM project from scratch.
+- Created: package.json, tsconfig.json, vitest.config.ts, .gitignore
+- Created: src/ directory skeleton (20 source files across 5 modules: schema, graph, analysis, frontmatter, error)
+- Created: test/ directory (5 placeholder test files: graph, analysis, schema, frontmatter, cost-benefit)
+- Modified: tasks/implementation/setup/project-init.md (status → completed)
+- Tests: 5 passing, npm install ✓, tsc --noEmit ✓