[BUG]: Human in the Loop: Canvas labels don't work in Condition/Response blocks #2962

Updated GitHub Issue - Combined Problems (No Block ID/UUID references)

Title:

[BUG] Human in the Loop: Canvas labels don't work + resumeInput not referenceable in downstream blocks

Describe the bug

Human in the Loop blocks have two critical issues preventing standard approval workflows:

1. Canvas labels don't work in Condition/Response blocks
2. resumeInput fields not accessible despite documentation

To Reproduce

Issue 1 - Labels don't work:

1. Create Human in the Loop block labeled "humanApproval"
2. Add Resume Input field approved (boolean)
3. Condition block → humanApproval.approved === true
4. Error: "humanApproval is not defined"

Issue 2 - resumeInput not referenceable:

1. Condition block → humanApproval.resumeInput.approved
2. Error: "resumeInput.approved doesn't exist on block. Available: url, resumeEndpoint, approved"

Expected behavior

Canvas labels should work like all other blocks:

✅ Agent("myAgent") → myAgent.output ✓
✅ API("getData") → getData.data ✓
❌ HITL("humanApproval") → humanApproval.approved ✗

Resume Input should work per docs:

Docs say: <blockName.resumeInput.fieldName>
Should work: humanApproval.resumeInput.approved
Reality: Only top-level "approved" field works

JSON Reality:

✅ "approved": false           ← Only this works
❌ "resumeInput": { ... }      ← Documented but broken

Screenshots

Canvas: "humanApproval" ✓
Error 1: "humanApproval is not defined" ✗  
Error 2: "resumeInput.approved doesn't exist" ✗
Docs:   "<blockName.resumeInput.fieldName>" ✗

Impact

Cannot build basic approval flows:

HITL → Condition → if(humanApproval.approved) → SMTP
              ↓                           ❌ Both paths broken
Expected: if(humanApproval.resumeInput.approved)

Additional context

• Only affects Human in the Loop blocks
• All other blocks use canvas labels correctly
• Documentation mismatch - <blockName.resumeInput.fieldName> doesn't exist
• Core workflow pattern broken - approval → condition → next step

Priority: Critical - blocks primary Human-in-the-Loop use case