Wave-5 chunk B: three model slots, search-engine row, first-run setup flow

Chunk B (owner-designed, model-slots wave) on the merged engine surface
(main 1d66a17):

AGENT SECTION — SLOTS ONLY (owner ruling)
- The six per-role model rows are GONE; three slot rows instead:
  Strong (Prober + Teacher), Cheap (five workhorse roles), Vision
  (visual maker + PDF reader), roster + resolved-default in every hint.
- Slot dropdowns share the app's menu language over the FEDERATED
  catalog (/api/models = keyed providers only, fresh per call — saving
  a key in Keys immediately widens the picker); the vision slot
  filters to image-capable models (Model.input); the menu's highlight
  now matches provider+id (ids can collide across providers).
- Slots write the new models section (PUT /api/settings/models) through
  the dialog's write seam; per-role overrides stay schema-only.
- ModelMenuList rows read 'provider · id' — federation makes the
  provider bookkeeping-relevant. Usage stamps render provider-qualified
  (prettyModel(qualified): 'Glm 5.3 Flash · openrouter') in the stats
  bar's turn lines.

SEARCH ENGINE (search wave: no default, owner)
- A row in Tools: Tavily/Brave via the shared-menu look, Automatic =
  the pin removed (auto-activation). The live reason line comes from
  /api/search; no engine key at all grays the whole row + disables the
  trigger (a keyless choice would only block auto-activation).

FIRST-RUN SETUP FLOW (owner design A: composer CTA + send interception)
- Chats cannot start until all three slots are picked — no defaults
  for 33 providers (slotsConfigured: all three slot models required).
- The graph view's new-session dock (home) shows a 'Set up your models'
  CTA while unconfigured; submitting a topic opens the SetupDialog WITH
  THE DRAFT PRESERVED; Save stores the models section and the queued
  message sends. Same interception on /chat/new sends.
- STAGED BY DEPENDENCY (owner: keys first, models after): no keyed
  provider → stage 1 deep-links the settings dialog on Keys (open now
  takes a section); a saved key reopens at stage 2 on the next submit.
- Stage 2: Strong → Cheap → Vision pickers (federated, vision-filtered,
  all three required). Closable without configuring — browsing stays
  possible; the gate is the send, not the dialog. Layered Esc: an open
  slot menu eats Esc before the dialog.
- Two closure bugs caught live: onDone→start/send captured the stale
  pre-save 'configured' (the flow now forces the replayed send); menu-Esc
  used to close the whole dialog.

Settings-dialog provider: open(section?) lands on a section (stage 1
deep-link). Tests: composeSlotModel/composeSearchEngine pure, slot SSR
replacing role rows, slotsConfigured/setupStage first-run gates,
provider-qualified prettyModel. Gates: typecheck, lint, 792/792, build.

app/chat/new/page.tsx

@@ -1,5 +1,6 @@
 import { NewSession } from "@/components/new-session";
-import { readDefaultSettings } from "@/src/server";
+import { readDefaultSettings, readSettingsRecord } from "@/src/server";
+import { slotsConfigured } from "@/src/core";
 
 export const dynamic = "force-dynamic";
 
@@ -16,5 +17,10 @@ export const dynamic = "force-dynamic";
  * only before the first-ever pick).
  */
 export default function NewSessionPage() {
-	return <NewSession initialSettings={readDefaultSettings()} />;
+	return (
+		<NewSession
+			initialSettings={readDefaultSettings()}
+			initialConfigured={slotsConfigured(readSettingsRecord()?.models)}
+		/>
+	);
 }