refactor: Move utility functions to @automaker/dependency-resolver

Consolidated dependency validation and ancestor traversal utilities:
- wouldCreateCircularDependency, dependencyExists -> @automaker/dependency-resolver
- getAncestors, formatAncestorContextForPrompt, AncestorContext -> @automaker/dependency-resolver
- Removed graph-view/utils directory (now redundant)
- Updated all imports to use shared package

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

libs/dependency-resolver/src/index.ts

@@ -7,5 +7,10 @@ export {
   resolveDependencies,
   areDependenciesSatisfied,
   getBlockingDependencies,
+  wouldCreateCircularDependency,
+  dependencyExists,
+  getAncestors,
+  formatAncestorContextForPrompt,
   type DependencyResolutionResult,
+  type AncestorContext,
 } from './resolver.js';