feat: ArizePhoenixTracer v2 - Enhanced Session Tracking and Flow Organization

[ialisaleh]

This PR introduces v2 of the ArizePhoenixTracer, significantly enhancing session tracing and Arize/Phoenix integration.

Key Improvements:

Per-Flow Projects: Each flow now creates a dedicated project in Arize/Phoenix for better tracking and organization.
Enhanced Root Span: Added session IDs, input blocks, and output blocks to capture detailed session-level insights.
Simplified Tracing: Removed unnecessary session IDs from individual component spans to reduce complexity and noise.
Codebase Refactor: Improved readability and maintainability through modularization and cleanup.

These updates streamline observability, improve integration, and enhance the overall user experience.

[Copilot]

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

src/backend/base/langflow/services/tracing/arize_phoenix.py:214

• Ensure processed_inputs contains the key 'input_value' to avoid potential KeyErrors.

self.chat_input_value = processed_inputs["input_value"]

src/backend/base/langflow/services/tracing/arize_phoenix.py:275

• Ensure the new _set_span_status method is covered by tests.

self._set_span_status(self.root_span, error)

[codspeed-hq]

CodSpeed Performance Report

Merging #5336 will degrade performances by 22.82%

_{Comparing ialisaleh:feat/arize-phoenix-tracer-v2 (b7828f3) with main (5a8d73c)}

Summary

⚡ 1 improvements
❌ 1 regressions
✅ 13 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	ialisaleh:feat/arize-phoenix-tracer-v2	Change
⚡	test_setup_llm_caching	2.1 ms	1.2 ms	+82.05%
❌	test_successful_run_with_output_type_any	248.2 ms	321.6 ms	-22.82%