[Devbook drift] .devbook/domain/sessions/domain.md#session-grouping #876

Scheduled Devbook verify run, 2026-09-30 (devbook:verify-change, kind domain-service).

Evidence: The code keeps both guarantees. The groups are ordered by name, or by enum order for the agent grouping, never by size. The code also has a third mode the chapter does not name, AgentSessionGrouping.None (one section with no name, which is the pane's default). Environment sections are keyed by id and named after the newest row. See the section below

Detail

• AgentSessionGrouping.None is a declared member and the pane's default (_grouping = AgentSessionGrouping.None). It yields one section with no name. Tests: AgentSessionGroupTests.Ungrouped_is_one_nameless_section_of_everything, Nothing_grouped_is_no_sections_at_all.
• Environment sections are keyed by EnvironmentId and named after the most recent row. Two machines with one name are two sections, sorted by name and then id. Tests: Two_environments_sharing_a_name_are_two_sections, A_section_is_named_after_its_most_recent_record.
• The groups are carved from SessionRows, run-only rows included, not from Agent Sessions.

Action: run devbook:capture-specs (kind domain-service) over .devbook/domain/sessions/domain.md#session-grouping and carry the plan in through flow-spec.

Read-only: nothing was run or written. The chapter carries no draft or proposed status, and no open pull request or change names it.