Wave 6 chunk A: sidebar context menu (Rename/Delete) + the two-option delete dialog

- Right-click any session row: MenuShell context menu, exactly two actions
  (owner ruling): Rename and Delete… — MenuShell discipline (placement,
  focus, arrow cycling, lh:menu-open announcements), agent-section's
  outside-click/Esc contract with [data-lh-menu] carve-outs.
- Rename is INLINE in the row (owner ruling): select-all entry, Enter/blur
  commits through the existing plumbing — PUT /api/chats/:id then
  lh:chat-renamed. The open chat header now LISTENS for the event too, so
  renaming the active session from the sidebar updates the header in place
  (it only dispatched before).
- Delete opens the two-option dialog (locked design, DELETE_OPTIONS pure
  seam for render pins): "Delete the session only" (preserve-graph — the
  graph keeps every contribution) vs "Also remove its graph traces"
  (delete-nodes — shared topics survive, only-this-session topics die).
  409 turn_in_flight/jobs_running and 503 extraction_winding_down render
  the server's line verbatim with a same-mode Try-again.
- Success: the sidebar patches its snapshot instantly, the active session
  navigates home (chat unmounts — drafts die with it), and lh:graph-revision
  announces the returned revision — the graph view refetches the snapshot
  AND costs (deletion is the one writer the status poll can't see).
- ChatDeleteMode type re-exported through the core barrel (the shell's one
  needed seam from core/graph-deletion.ts).

Gates: tsc clean, 909/909, lint 0, build ok. Live-verified on :3001:
context menu open/Esc, inline rename (row + API + active header), both
delete modes on scratch sessions, simulated 409 + retry-then-succeed,
active-session navigation home, graph+costs refetch deltas on home.

src/core/index.ts

@@ -40,6 +40,11 @@ export * from "./fuzzy.ts";
 // the user-settings record's shape/sanitizer (pure) and its fully-resolved
 // view. Browser-safe — the Wave-4 panel imports these directly.
 export * from "./settings.ts";
+// graph-deletion.ts (wave 6): the whole module is PURE but storage-port
+// driven — the deletion RUNS server-side only. The shell needs exactly one
+// thing from it: the ChatDeleteMode union (the delete dialog's two-option
+// design + the DELETE query param), hence this type-only re-export.
+export type { ChatDeleteMode, ChatDeletionStats } from "./graph-deletion.ts";
 export * from "./settings-resolution.ts";
 export * from "./search.ts"; // search port (search wave, 2026-09-20)
 // auth-keys.ts (auth-keys wave, 2026-09-19): the curated key catalog +