feat(studio): add runtime-aware agent workflows

[evanlowe]

Summary

• add region-scoped Runtime browsing and propagate the selected Runtime region through creation, details, connection, update, evaluation, and deletion
• expose generated-agent debug traces and compact empty read-only workflow nodes while fixing agent detail navigation and actions
• probe capabilities on connection, dynamically mount missing image, video, and presentation tools per session, and add concise enterprise prompt suggestions
• share local Studio sandbox configuration across temporary chat and Skill creation modes
• add the presentation generator, capability contracts, frontend production assets, and regression coverage

Validation

• cd frontend && npm test — 277 passed
• cd frontend && npm run build — passed
• uv run pytest — 968 passed, 6 skipped
• uv run pre-commit run --all-files — Ruff, formatting, and gitleaks passed
• Pyright reports no new errors from this change; four existing errors remain in the touched AgentKit integration modules

Notes

• Studio lists one selected region per request and defaults to Beijing. Runtime operations require the Runtime region instead of falling back to a legacy default.
• Task tools are session-mounted only when absent, so existing Agent tools are not overwritten.