[trissim]

Change

Follow-up to #693, based on its78361008 head. The Core status-owner fix stays on #693; this does not change it or unread().

The 0-or-1 widget-class tuple was an Optional disguised as a collection. Delete that factory loop and make each kind choose actual composition:

• abstract ConversationKind.compose_activity(view);
• Channel explicitly composes nothing; IRC inherits that channel behavior;
• DM selects CommsChatView.compose_dm_activity, where the view constructs/owns/yields its SessionDetails with the required history/status source;
• remove the kind module's SessionDetails import; the composing view imports it.

Do not reset channel thread_activity to None: ThreadStatusOwner already owns that absent default. No empty widget, extra state, or factory mutating its caller.

Evidence

Compared with #693: two production files, +15/−12.

activity_widgets: three declarations + one consumer →0. Shared widget-class construction loop1→0. Kind-side widget import1→0. View-owned DM composition0→1. No new channel status-field assignment. status_text, mentions, unread handling, history and Core pin are unchanged from #693.

NRA Package source enumeration covered Toad281/Core328/Textual254 modules: 863 parsed, zero omissions. Before/after declarations, writes, decisions, inheritance/imports and consumers: .artifacts/channel-active/composition-{before,after}.txt, including the actual ThreadStatusOwner declaration/consumers. Dynamic composition callbacks/MRO are not proved by AST; their implementations were read separately.

Receiving ratchet against78361008 exit0, no positive deltas. ForeignAbsenceProbe: kind6→6, chat3→3. Output .artifacts/channel-active/composition-ratchet.json.

No automated Toad tests, fixtures or source-overlay application. Real DM/channel composition verification awaits approved normal installation with #693/Core#987, using the accepted XvfbDisplay.input helper by path. No installed/live-success claim. Draft for Claude review; do not merge independently ahead of #693.

[trissim]

Superseded by the corrected kind-owned composition folded into #693. The source checkpoint remains published.