update src/nodes/pedagogy_agent.py

fix: Mercury-2/Gemini refs in src/nodes/socratic_generator.py

sync: full source tree (all code, no binaries/secrets)

sync: src/nodes/socratic_generator.py

fix: src/nodes/socratic_generator.py

fix: diagnostic scoring threshold and keyword lists

fix: honest feedback on idk in assessment and tutor phases

fix: 4 questions per topic in diagnostic bank

fix: src/nodes/pedagogy_agent.py

feat: YouTube recommendations in wrapup, mastery-driven

fix: clean up stale Chainlit refs from Sanika branch

fix: clean up stale Chainlit refs from Sanika branch

fix: all LLM calls via OpenRouter

feat: pilot survey — post-quiz + Likert + CSV