Harden Multipath Stream Discovery

Google Maps now has both a file/import path and an API-backed Data Portability path, and agent hosts still vary in how much MCP tool output they expose. The reference needs a durable rule for reusing stream definitions across acquisition paths without erasing source identity, and MCP search needs to put a usable fetch handle where clipped previews still show it.

The refresh synthesis places connection and device in the reference layer, not PDPP Core. The read surface may expose connection_id as grant-safe attribution, but collection mechanics such as upload, local export, browser automation, and provider OAuth must not become stream identity.

The MCP adapter SHALL include a parseable first fetch handle in the model-visible search tool content[] text whenever the search result page contains at least one fetchable hit. The first handle SHALL appear before verbose source/package metadata such as source_mix, so clients that clip or summarize tool output still expose a usable handle. The handle SHALL match the first entry in structuredContent.results[0].id.

The reference implementation SHALL allow multiple connector types, setup methods, or acquisition paths to emit records for the same normalized stream definition when the stream semantics and record shape match. Record storage, runtime state, schedules, diagnostics, and grant-safe read attribution SHALL remain scoped to connectionid / connectorinstance_id, not to the acquisition path alone.