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

.gitignore

@@ -0,0 +1,23 @@
+# Dependencies
+node_modules/
+
+# Build output
+dist/
+
+# Source maps
+*.js.map
+
+# Environment
+.env
+.env.*
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Coverage
+coverage/