iOS remote: transcript fidelity + mid-session controls & model catalog

Bring NucleicRemote closer to desktop parity in two areas (the core
sync loop was already at parity — shared protocol, control scope).

Transcript fidelity (iOS): a client-side TranscriptProjection coalesces
streaming text by messageID and folds each tool call's lifecycle
(start/deltas/complete/result/fileChange) into one expandable card —
fixing the duplicate started+completed rows. Adds Markdown bubbles, the
gold Orchestra card for Task/Agent spawns, and the previously-dropped
usage/cost, rate-limit, file-change, turn-boundary and session-started
rows, plus a context-window % header badge.

Mid-session controls + model catalog (protocol/host/iOS): project the
host ModelCatalog over the wire as WireModelCatalog (in Welcome); add 5
control-scope setters (setSessionModel/Effort/Auto/AutoShip/ShipBranch)
backed by the existing AppStore.mutateSession + SessionController hooks;
enrich WireSessionSummary with model/effort/auto/autoShip/shipBranch/
contextInputTokens (all forward-compatible). The composer gains a model
picker and a catalog-driven effort menu (per-backend caps: Codex→xhigh,
Grok→auto), and the session header gains a model/effort/auto/autoship
control bar.

Tests: CBOR round-trips for the new messages, Welcome.modelCatalog, the
new summary fields, forward-compat decode of old bytes, and the setters
reaching the host. Verified in the Simulator (NUCLEIC_DEMO=1).

Co-Authored-By: Claude Opus 4.8 <[email protected]>

NucleicRemote/NucleicRemote/Views/Composer.swift

@@ -8,12 +8,14 @@ struct StartChatComposer: View {
     @State private var projectID: ProjectID?
     @State private var draft = ""
     @State private var auto = false
+    @State private var model: String?
     @State private var effort = MobileEfforts.fallback
 
     private var projects: [WireProject] { store.dashboard.projects }
     private var selected: WireProject? {
         projects.first { $0.id == projectID } ?? projects.first
     }
+    private var controlled: Bool { selected?.isNucleicControlled ?? false }
 
     var body: some View {
         VStack(alignment: .leading, spacing: 10) {
@@ -28,7 +30,6 @@ struct StartChatComposer: View {
                         .font(.subheadline)
                 }
                 Spacer()
-                EffortMenu(effort: $effort, controlled: selected?.isNucleicControlled ?? false)
                 Toggle(isOn: $auto) {
                     Label("Auto", systemImage: auto ? "bolt.fill" : "bolt.slash")
                 }
@@ -36,14 +37,20 @@ struct StartChatComposer: View {
                 .tint(Palette.accent)
                 .font(.caption)
             }
+            HStack {
+                // The model also selects the backend, so the home composer offers every provider.
+                ModelMenu(model: $model, catalog: store.modelCatalog, backend: nil)
+                Spacer()
+                EffortMenu(effort: $effort, catalog: store.modelCatalog, modelSKU: model, controlled: controlled)
+            }
             HStack(alignment: .bottom, spacing: 8) {
                 TextField("Describe a task…", text: $draft, axis: .vertical)
                     .textFieldStyle(.roundedBorder)
                     .lineLimit(1...5)
-                    .orchestraGlow(active: MobileEfforts.isOrchestra(effort) && (selected?.isNucleicControlled ?? false))
+                    .orchestraGlow(active: MobileEfforts.isOrchestra(effort) && controlled)
                 Button {
                     if let project = selected {
-                        store.startChat(in: project.id, message: draft, effort: effort, auto: auto)
+                        store.startChat(in: project.id, message: draft, model: model, effort: effort, auto: auto)
                         draft = ""
                     }
                 } label: {
@@ -56,6 +63,14 @@ struct StartChatComposer: View {
             }
         }
         .card()
+        // Switching to a model with a lower effort cap can't leave an unsupported level selected.
+        .onChange(of: model) { _, newModel in
+            let levels = store.modelCatalog.offeredEfforts(forModel: newModel)
+            let sentinel = store.modelCatalog.orchestraSentinelOrFallback
+            if effort.caseInsensitiveCompare(sentinel) != .orderedSame, !levels.contains(effort) {
+                effort = levels.last ?? MobileEfforts.fallback
+            }
+        }
     }
 }