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

[zyn080302]

Summary

• add Studio Harness Sidecar optimization scenarios and component selection
• preserve selected profile and components when materializing debug variants into publish drafts
• route managed Sidecar releases through the structured AgentKit CLI flow with exact-name, single-instance, and readiness safeguards
• keep zero selected components on the ordinary Runtime path
• add focused frontend and Python regression coverage and refresh bundled WebUI assets

Verification

• npm run test:harness-sidecar-coverage: 8/8, 100% statements/branches/functions/lines
• npm test: 476/476
• focused Python tests: 76 passed
• npm run build: passed; existing chunk-size warnings only
• pre-commit: Ruff check, Ruff format, and hardcoded-secret detection passed
• git diff --check: passed