Route Memory maintenance diagnostics to their owner

[hamzamerzic]

Summary

• retain declared document ownership in the generated graph index
• give maintenance diagnostics stable code, path, and owner identities and deduplicate them at the host boundary
• send only writer-owned defects to the nightly analyst while recording app-owned warnings in run status and update history
• document that managed documents are not prose follow-ups for the writer

Why

The nightly writer could be told to split an app-owned architecture note that its own validation contract forbids it from changing. The unresolved warning then returned as slightly different prose on later runs. Routing diagnostics by ownership removes the impossible task without weakening graph-quality checks for writer-owned notes.

Verification

• MOBIUS_FRONTEND_NODE_MODULES=/data/platform/frontend/node_modules npm test — 46 JavaScript checks, the five-phase offline harness, and the Python suite passed
• canonical app validation passed with zero errors or warnings
• git diff --check