Advertise internal worker launches and temporary source writes through the
canonical effects owner so MCP hints and session availability agree with
existing analysis behavior. Preserve non-destructive, idempotent semantics.
Verify public metadata boundaries and a real Obsidian CLI/MCP workflow,
retaining compact reproduction and cost records.
Fixes#3867
Co-authored-by: Kaoru0822 <208281322+kaoru0822-kitauji@users.noreply.github.com>