[Fix] Discover pages inside shared Notion databases

[mrubens]

Problem

Pages that live inside Notion databases (database rows) were missing from both the Memory (gbrain) collector and the deployment Notion MCP.

Root cause: Notion's search API only guarantees content directly shared with an integration — rows inherit access through their database but rarely appear in the search index (documented limitation). The collector's sweep searches object: page only, and the traversal phase (#1726) could only discover databases embedded as child_database blocks inside already-inventoried pages. A database shared directly with the integration (e.g. a top-level database) was therefore invisible: its rows never entered Memory. The MCP proxied the same search index, and a database ID couldn't be fetched at all (pages/{id} and data_sources/{id} both 404 for it).

Changes

Collector (apps/bullmq/.../notion-pages.ts)

• The traversal phase now first enumerates every shared data source via search with filter: data_source, feeding each into the existing data_source query path so their rows ingest like any other discovered page.
• The enumeration is durable across passes (dataSourceCursor/dataSourcesDone in the traverse state) and backward-compatible with in-flight cursors; an expired search cursor restarts the enumeration instead of wedging the collector.

MCP (apps/api/.../notion/tools.ts)

• notion-fetch gains object_type: "database" (GET databases/{id}), so agents can resolve a database ID to its data sources.
• notion-search's description now steers agents around the index gap: find the data source, then list rows with notion-query-data-sources.

Docs: apps/docs/integrations/notion.mdx describes the database-row discovery.

Tests

• New: directly-shared data-source discovery; stale-cursor restart of the enumeration.
• Existing traversal tests pinned to dataSourcesDone: true to keep their original focus.
• All 23 collector tests and 7 MCP tests pass; lint, types, and knip clean.

Note: verified against Notion's API docs and unit tests (no live Notion connection in local dev). After deploy, missing rows are picked up on the next daily sweep → traverse cycle.

[roomote-community]

No code issues found. See task

_{Reviewed f56c39f}