feat(studio): add Harness Sidecar optimization and release flow

[zyn080302]

Summary

• add Studio Harness Sidecar optimization scenarios, profile/component selection, deployment validation, and read-only details
• • preserve selected Sidecar settings across debug, publish, and Runtime update flows while keeping zero selected components on the ordinary Runtime path
• • ship the public Sidecar integration source in veadk-python[harness-sidecar]; no separate integration wheel is required
• • route managed Sidecar releases through the structured AgentKit CLI flow with immutable-base, exact-name, single-instance, registry anchoring, readiness, and active-plan safeguards
• • keep agentkit-sdk-python at the released 0.8.1 compatibility boundary; the managed base provides that SDK and the temporary Sidecar requirements no longer resolve or replace it
• • preserve ordinary project requirements and non-Sidecar deployment behavior
• • add focused frontend/Python coverage, CI release gates, and refreshed bundled WebUI assets

Sidecar build contract

• managed Sidecar staging removes veadk-python, agentkit-sdk-python, and the retired integration distribution only from the temporary managed build context
• • the managed Dockerfile still verifies that the base contains agentkit-sdk-python 0.8.1

Verification

• Python full suite: 2332 passed, 6 skipped, 6 subtests passed
• • focused managed-source and deployment regression: 78 passed
• • frontend full suite: 698 passed
• • Harness Sidecar frontend coverage: 17 passed, 100% statements/functions/lines and 97.36% branches
• • npm run build: passed; existing chunk-size warnings only
• • Ruff check and format: passed
• • targeted Pyright for managed_sidecar_source.py: 0 errors
• • all-file pre-commit and hardcoded-secret detection: passed
• • git diff --check: passed
• • no cloud build, Runtime mutation, or Studio restart was performed for this update

Compatibility

Customers that do not select Harness Sidecar continue to use the existing dependency and deployment path. Managed Sidecar builds fail closed unless the operator provides an immutable @sha256 base containing agentkit-sdk-python 0.8.1.