Distribute matched prebuilt assets and simplify Runtime onboarding

[SaladDay]

Core installation previously carried execution payloads before an operator added a node, and self-hosted Runtime setup required manual assembly. This change provides a thin matched Core/Web/PostgreSQL bundle, verified on-demand Runtime assets, cached one-command node installation with authenticated readiness, and one-command self-hosted setup using Environment-scoped credentials. Local Docker/microsandbox installation remains optional; the default has zero nodes.

Self-hosted setup reuses V1 Docker Runtime and the existing credential issuer. Issuance enforces project, tenant and creator ownership; retries retain the original container and history. The release workflow builds Linux amd64 assets and optionally creates an unpublished draft. It does not deploy or publish automatically.

Validation:

• Actual thin-bundle Core/Web/database installation passed on mx1. Thin archive 218.32 MiB versus 905.24 MiB offline. Docker node cold setup took 16.04 s on the test network; cached Docker/microsandbox retries took 0.77/0.97 s with zero asset downloads/imports.
• Both node providers passed real Kimi/Codex execution, Files/Artifacts, Core/node restart continuation, cancellation and cleanup. Self-hosted Codex/Claude with Kimi and MiniMax Code with MiniMax passed execution, Files/Artifacts, original-container recovery, cancellation, SDK 3.13.0 reads, credential isolation and revocation.
• MiniMax shortened a requested cancellation-test filename. The strict probe failed; public cancellation of the observed native command then stopped its real file growth. Both records are retained; no model-output repair.
• 80 installer and 8 manifest tests pass. The detached-package local microsandbox installation was verified on mx1 after correcting an obsolete prerequisite; Core/Web healthy and local Provider ready.
• Full make check ran against integrated c5cb6b5. Go/PostgreSQL, SQL generation, SDK, Claude and Web unit/type/build checks passed; browser acceptance was 122/127. Four existing Dashboard failures remain WEB-TEST-002; the additional startup timeout passed three isolated reruns. Remaining MiniMax/Rust gates passed separately. The full gate is not green. Tests use dedicated resources, serialized Go package execution and Chromium rather than configured Chrome.
• Latest upstream main 0035435 is integrated. Fresh independent Astra high review of the final full diff found no blockers; the earlier review finding was corrected and verified. Post-integration daemon/Core/console Go tests, real PostgreSQL tests, Web/client unit tests, type checks, OpenAPI no-drift and SQL generation checks passed.

Limits: actual execution artifacts include an explicitly trusted private test CA and are not published production releases. Acceptance source is 64f5745, with the focused local-installer fix tested as an explicit overlay; latest upstream integration is checked separately. No claim that Actions publication or external public-domain installation has run. No upgrades, provider migration, new execution architecture, additional platforms or npm publication.