docs(rfc): define scope organization and agent integration

[PsiACE]

Which issue or RFC does this PR close?

Refs #1219 #1238 .

Rationale for this change

The current Scope model does not clearly separate ownership, hierarchy, sharing, delivery, and reporting. This RFC defines how these concerns work together without adding another Project identity.

What changes are included in this PR?

• Add the RFC in English and Chinese.
• Define Scope ownership, Parent, Context References, Artifact publication, and observation selection.
• Describe Agent binding, Agent handoff, Dashboard aggregation, and Handoff Report behavior.
• Define how integrations should allocate Scope IDs and remove the dependency on project_id.

Are there any user-facing changes?

No. This PR only adds documentation. It does not change runtime behavior, public APIs, or persisted data.

The RFC describes proposed API and data model changes for later implementation.

How was this change tested?

make docs-test
git diff --check

The commit hooks also passed.

AI usage statement

Used Codex with GPT-5 to inspect the repository and help draft and edit the RFC.