Gate Orchestra behind Nucleic Control; lavender Home composer accent

Orchestra is a Nucleic Control capability now:
- Core: SessionController withholds the fan-out consent unless the session's project
  is under Control (resolvedEffort still maps the sentinel to xhigh, so a stray
  selection never reaches a backend verbatim). Covered by a new SessionController test.
- macOS: the effort menu shows Orchestra disabled with a 'Requires Nucleic Control'
  note + tooltip off-control; effectiveEffort demotes a carried-over selection so the
  label/glow never show it active where it can't run.
- Home composer themes lavender (the Control accent) for a Control project — the
  Auto/Merge accents and a persistent ring on the field, tracking the project picker.
- Remote: WireProject carries isNucleicControlled (decode-tolerant) so the iOS effort
  picker gates Orchestra the same way.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

NucleicRemote/NucleicRemote/Views/Composer.swift

@@ -28,7 +28,7 @@ struct StartChatComposer: View {
                         .font(.subheadline)
                 }
                 Spacer()
-                EffortMenu(effort: $effort)
+                EffortMenu(effort: $effort, controlled: selected?.isNucleicControlled ?? false)
                 Toggle(isOn: $auto) {
                     Label("Auto", systemImage: auto ? "bolt.fill" : "bolt.slash")
                 }
@@ -40,7 +40,7 @@ struct StartChatComposer: View {
                 TextField("Describe a task…", text: $draft, axis: .vertical)
                     .textFieldStyle(.roundedBorder)
                     .lineLimit(1...5)
-                    .orchestraGlow(active: MobileEfforts.isOrchestra(effort))
+                    .orchestraGlow(active: MobileEfforts.isOrchestra(effort) && (selected?.isNucleicControlled ?? false))
                 Button {
                     if let project = selected {
                         store.startChat(in: project.id, message: draft, effort: effort, auto: auto)