Add support to search in multiple rooms.

While Riot exposes searching across a single or all rooms only. A single room might have multiple ancestors due to room upgrades. This makes it necessary to search across multiple rooms when the user wants to search in a single room.

Either Seshat should learn about room ancestors and do this transparently or it should have the ability to define multiple rooms for a search.

In both cases a better query parser would likely be necessary.

The issue names no files or tests. Start by tracing Seshat’s search entry point and query parser, then determine how room ancestors or an explicit room list should be represented. Done means a single-room search can cover multiple related rooms with unambiguous query behavior.

Written by the indexing model from the issue text.