fix(workflow): prevent panic on invalid object schema type during canvas conversion

[phpoh]

Summary

This PR fixes issue #2622 where workflow panics when object schema is a map[string]any instead of the expected []any slice during canvas type conversion.

Problem

The code in type_convert.go uses direct type assertions like v.Schema.([]any) in multiple places. When the schema is not a slice (e.g., a map), this causes a panic instead of returning a proper error.

Solution

Replace all direct type assertions with safe type checks using the comma-ok idiom:

// Before (panics on invalid type)
for _, subVAny := range v.Schema.([]any) {

// After (returns error on invalid type)
schemaList, ok := v.Schema.([]any)
if !ok {
    return nil, fmt.Errorf("object schema must be []any, got %T", v.Schema)
}
for _, subVAny := range schemaList {

Affected Functions

• CanvasVariableToTypeInfo
• CanvasBlockInputToTypeInfo
• BlockInputToNamedTypeInfo
• VariableToNamedTypeInfo

Testing

Added comprehensive unit tests covering:

• Valid []any schema (should succeed)
• Invalid map[string]any schema (should return error, not panic)
• nil schema (should succeed)
• Other invalid types (should return error)

All tests pass.

Test plan

• Run unit tests: go test ./domain/workflow/internal/canvas/convert/... -v
• Build verification: go build ./domain/workflow/...
• Test cases cover both valid and invalid schema types

🤖 Generated with Claude Code

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