feat(tabs): 2-column tab grid with nestable subagent groups + tab menu (add/remove from group)

1 files changed, 1 insertions, 0 deletions

diff --git a/GLOSSARY.md b/GLOSSARY.md
index 1c1b68d..70660d9 100644
--- a/GLOSSARY.md
+++ b/GLOSSARY.md
@@ -43,6 +43,7 @@
 | **surface catalog** | The list of available surfaces (metadata) the FE fetches to discover them (`GET /surfaces`). | capability manifest |
 | **view** | RESERVED — the old-Dispatch sidebar affordance (settings / feature views); a FUTURE FE concept, NOT a surface. | (do not reuse) |
 | **tab** | A FE workspace slot in the tab strip that *references* one open conversation — holds its `conversationId`, the selected **model name**, and a derived title. Distinct from the conversation itself (the backend thread): closing a tab forgets it LOCALLY (drops the slot + evicts its FE cache); the conversation persists server-side. Open tabs + the active tab are persisted locally. | (do not conflate with **conversation**) |
+| **subagent group** / **tab group parent** | The tab grid's purely VISUAL nesting: a tab whose `tabGroupParentId` (backend-owned, EFFECTIVE value — an explicit user override, else the lineage `parentConversationId`) names another open tab renders inside that tab's subagent group (a darker box; the group parent's card is double-width). Users regroup via the tab menu (right-click / touch-and-hold) → `PUT /conversations/:id/tab-group`; synced by `conversation.tabGroupChanged`. Never affects lineage, manageability or agent behaviour. | (do not conflate with lineage **parentConversationId**) |
 | **feature module** | A self-contained FE feature (chat, history explorer, …); feature-as-a-library, composed at the root. | — |
 | **composition root** | The single place (`src/app/`) that imports + wires feature modules + the surface host. | — |
 | **surface interpreter** | The generic renderer: field kind → component. Knows kinds, never surface ids. | — |