feat(core): orphaned-flow diagnostic

[mahyarmlk]

Summary

Implements the orphaned-flow graph diagnostic for inspectScreen.

A flow is "orphaned" when it has one or more steps but none of its steps appear in any surface. This diagnostic helps catch incomplete or disconnected flow definitions during development.

Changes

• packages/core/src/graph.ts: Added orphaned-flow diagnostic emission in computeDiagnostics with nested flow metadata (flowNodeId)
• packages/core/src/core.test.ts: Added 9 test cases covering:
  • No flows → no orphaned-flow
  • Empty flow → no orphaned-flow
  • All steps unsurfaced → emits orphaned-flow
  • At least one surfaced step → no orphaned-flow
  • Multiple flows reporting only orphaned ones
  • Nested flow.flowNodeId and flow.flowSemanticNodeId
  • nodeId and semanticNodeId left undefined
  • Deterministic ordering
  • Coexistence with flow-step-not-surfaced
• .changeset/shy-kids-grow.md: Minor bump for @intent-framework/core

Diagnostic shape

{
  severity: "warning",
  code: "orphaned-flow",
  message: "\"<flow name>\" has no surfaced steps.",
  flow: {
    flowNodeId: "<flow node id>",
    flowSemanticNodeId: "<flow semantic id if available>"
  }
}

Validation

• pnpm test ✅ (161 passed)
• pnpm typecheck ✅
• pnpm build ✅
• pnpm lint ✅
• pnpm pack:check ✅
• pnpm changeset status ✅