refactor: remove Azure OpenTelemetry integration and implement core RAG pipeline orchestration with backend setup

Fix: Add mandatory service.name to OTEL Resource for Azure Ingestion

Diag: Use manual AzureMonitorTraceExporter for lower-level control and debug

Diag: Add manual test span to /api/diag for connectivity verification

Fix: Pin OpenTelemetry and Azure SDK versions for stability

Fix: Restore main.py logic and switch to direct uvicorn for tracing stability

Diag: Add /api/diag endpoint and improved Azure Monitor initialization logic

Fix: Improve Azure Monitor initialization and robust connection string parsing

Feat: Add Azure AI Foundry Tracing and update documentation

Docs: Update system documentation with latest model info and recent feature improvements

Fix: Graceful error handling - never show blank responses on errors

Fix: Allow employee role to query cross_department_route (Comcast/general queries)

Loosen output guardrails preventing ungrounded/citation false positives

Fix overzealous off_topic_keyword string matching

Fix UI displaying duplicate sources for the same page/document

Fix accessible_collections UI display bug

Fresh cleaner push without any mp4