fix(examples-py): validate Together, Vertex AI, and Watson Orchestrate ADK OTel 2.x spans

[Nightingalelyy]

Summary

• Validate the Python Together, Vertex AI, and Watson Orchestrate ADK instrumentation fixes with committed current-SDK examples.
• Use deterministic real-SDK parsing by default, semantic workflow inputs, exact marker/group metadata, timeout-aware aggregate runners, and explicit client/Respan teardown.
• Add connected tool rounds, sync/async streaming, non-chat Together surfaces, controlled provider failures, and credential-gated live service paths.

Validation

• Example contract tests: Together 4/4, Vertex AI 5/5, Watson Orchestrate ADK 4/4 (13/13).
• Root-config Ruff check and format check pass for all three changed example directories.
• Local editable links resolve the exact companion instrumentation package paths.
• All 22 processes completed under otel2-fix-py-group-27-20260818T102109Z; 19 deterministic traces exported and three credential-gated live scripts skipped explicitly.
• Respan MCP audit opened every one of the 19 trees and 43 full details; hierarchy, IDs, parents, content, models/providers, usage, stream flags, tools, errors, grouping, privacy bounds, and exact marker propagation were checked.
• Together exported 9 traces/20 records, Vertex AI 5 traces/12 records, and Watson Orchestrate ADK 5 traces/11 records with no duplicates or orphans.
• Git diff checks pass and requirements remain registry-portable with no committed local editable paths.

External follow-ups

• Current ingestion leaves convenience tools/tool_calls arrays empty despite canonical definitions/calls, derives some provider IDs from model namespaces, and projects native OTel 429/503/500 errors as success/200 with estimated tokens.
• Direct Together, authenticated Vertex AI, and live Watson service runs remain credential-gated.
• Release publication must synchronize the instrumentation manifests with the aggregate >=0.1.1 floors.

Companion examples

• Instrumentation PR: fix(instrumentation-py): repair Together, Vertex AI, and Watson Orchestrate ADK OTel 2.x spans respan#393