fix: image_placeholder_generator skipped in direct generate_section path

[JNK234]

Problem

In root/backend/agents/blog_draft_generator_agent.py (lines 324-351), generate_section calls nodes directly in sequence but skips image_placeholder_generator between code_example_extractor and quality_validator.

The graph definition in graph.py (line 90) includes this node. Sections generated via the per-section API path will never have image placeholders.

Fix

Add image_placeholder_generator call in the generate_section method's node sequence.

Files to Change

• root/backend/agents/blog_draft_generator_agent.py