[paseo] bug: Cursor provider does not surface injected Paseo MCP tools; agent-scoped delegation falls back to CLI and loses finish notifications

## Observed symptom bug: Cursor provider does not surface injected Paseo MCP tools; agent-scoped delegation falls back to CLI and loses finish notifications In a Paseo Desktop agent tab with the **Cursor provider**, Paseo injects the internal `paseo` MCP server into the session config (`withRuntimePaseoMcpServer`), but the model never sees `create_agent` or the other delegation tools. It falls back to `paseo run -d` via Shell, which works but loses MCP-only behavior (notably `notifyOnFinish`; the CLI-side gap is tracked separately in #3248). **What this blocks:** unattended delegation loops. My workflow has a parent agent spawn a child via MCP `create_agent` (default `notifyOnFinish: true`), end its own turn, and rely on the finish notification to wake up and continue — e.g. spawn a reviewer, wake when it goes idle, apply its findings, repeat. With the Cursor provider as parent, the loop stalls after the first delegation: the child finishes and the parent never wakes. ## Environment GitHub getpaseo/paseo #5091 ## Trigger / context Public GitHub report in getpaseo/paseo (FRESH_14D). ## Source evidence - https://github.com/getpaseo/paseo/issues/5091 (2026-09-20T03:50:23Z) — evidence_class: PRIMARY_ISSUE_REPORT — #5091 ## Freshness - classification: FRESH_14D - retrieved_at: 2026-10-02T10:48:57.646025Z - scout_id: Cfdf53dd72e ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.