Don't invent stacks from name prefixes by default (#12)

App/AppState.swift

@@ -143,8 +143,11 @@ final class AppState {
     }
 
     /// Recompute stacks + standalone from the current container list and known projects.
+    /// Name-prefix inference for externally-launched containers is opt-in (default off) so
+    /// unrelated containers that merely share a prefix aren't grouped into a fake stack (#12).
     private func reassemble() {
-        let result = registry.assemble(containers: containers)
+        let infer = UserDefaults.standard.bool(forKey: "groupByNamePrefix")
+        let result = registry.assemble(containers: containers, inferStacks: infer)
         stacks = result.stacks
         standalone = result.standalone
     }

App/ConsaiApp.swift

@@ -16,6 +16,15 @@ enum ConsaiEntry {
                 exit(0)
             }
             app.run()
+        } else if let i = args.firstIndex(of: "--render-live") {
+            let dir = URL(fileURLWithPath: i + 1 < args.count ? args[i + 1] : "shots")
+            let app = NSApplication.shared
+            app.setActivationPolicy(.accessory)
+            Task { @MainActor in
+                await ShotRenderer.renderLive(to: dir)
+                exit(0)
+            }
+            app.run()
         } else if let i = args.firstIndex(of: "--render-icon") {
             let out = URL(fileURLWithPath: i + 1 < args.count ? args[i + 1] : "icon.png")
             let app = NSApplication.shared

App/Shots/ShotRenderer.swift

@@ -45,6 +45,18 @@ enum ShotRenderer {
         FileHandle.standardError.write(Data("rendered shots to \(dir.path)\n".utf8))
     }
 
+    /// Capture the panel backed by the REAL AppState (live daemon), for QA/authentic shots.
+    /// Refreshes twice with a gap so CPU% (needs two samples) populates.
+    static func renderLive(to dir: URL) async {
+        try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+        let state = AppState()
+        await state.refresh()
+        try? await Task.sleep(for: .seconds(2.5))
+        await state.refresh()
+        await shoot(PanelView().environment(state), width: 360, height: 600, name: "live-panel", dir: dir)
+        FileHandle.standardError.write(Data("rendered live panel to \(dir.path)\n".utf8))
+    }
+
     private static func shoot<V: View>(_ view: V, width: CGFloat, height: CGFloat, name: String, dir: URL) async {
         let themed = view.frame(width: width, height: height)
             .preferredColorScheme(.dark).tint(Theme.jade)

App/Views/SettingsWindow.swift

@@ -7,6 +7,7 @@ struct SettingsWindow: View {
     @Environment(AppState.self) private var appState
     @AppStorage("pollOpen") private var pollOpen = 2.0
     @AppStorage("pollClosed") private var pollClosed = 15.0
+    @AppStorage("groupByNamePrefix") private var groupByNamePrefix = false
     @State private var working = false
 
     var body: some View {
@@ -38,6 +39,12 @@ struct SettingsWindow: View {
                 }
             }
 
+            Section("Stacks") {
+                Toggle("Group external containers by name prefix", isOn: $groupByNamePrefix)
+                Text("Off: only stacks you launch through Consai are grouped (reliable). On: containers that share a `name-` prefix are grouped as inferred stacks — can mis-group unrelated containers.")
+                    .font(.caption).foregroundStyle(.secondary)
+            }
+
             Section("Refresh cadence") {
                 LabeledContent("Panel open") {
                     Stepper("\(pollOpen, specifier: "%.0f")s", value: $pollOpen, in: 1...10)

ConsaiCore/Sources/ConsaiCore/Engines/ProjectRegistry.swift

@@ -45,7 +45,16 @@ public struct ProjectRegistry: Codable, Sendable, Equatable {
     // MARK: - Assembly
 
     /// Fold containers into stacks + standalone leftovers.
-    public func assemble(containers: [Container]) -> (stacks: [Stack], standalone: [Container]) {
+    ///
+    /// - Parameter inferStacks: when true, containers Consai didn't launch are grouped by
+    ///   `<project>-<service>` name prefix (best-effort, marked `.inferred`). This can
+    ///   over-group unrelated containers that merely share a prefix (e.g. `qa-web` + `qa-cache`),
+    ///   so it defaults to **false** — only Consai-launched stacks group reliably. Callers
+    ///   opt in via a user setting.
+    public func assemble(
+        containers: [Container],
+        inferStacks: Bool = false
+    ) -> (stacks: [Stack], standalone: [Container]) {
         var remaining = containers
         var stacks: [Stack] = []
 
@@ -64,29 +73,30 @@ public struct ProjectRegistry: Codable, Sendable, Equatable {
             )
         }
 
-        // 2. Inferred stacks: group leftovers by candidate prefix (before the last "-").
-        var byCandidate: [String: [Container]] = [:]
+        // 2. Inferred stacks (opt-in): group leftovers by candidate prefix (before the last
+        //    "-"). Off by default — see issue #12 — so unrelated containers sharing a prefix
+        //    aren't grouped into a fake stack.
         var standalone: [Container] = []
-        for container in remaining {
-            if let candidate = Self.inferredProject(from: container.name) {
-                byCandidate[candidate, default: []].append(container)
-            } else {
-                standalone.append(container)
+        if inferStacks {
+            var byCandidate: [String: [Container]] = [:]
+            for container in remaining {
+                if let candidate = Self.inferredProject(from: container.name) {
+                    byCandidate[candidate, default: []].append(container)
+                } else {
+                    standalone.append(container)
+                }
             }
-        }
-        for (candidate, members) in byCandidate {
-            if members.count >= 2 {
-                stacks.append(
-                    Stack(
-                        projectName: candidate,
-                        composeFilePath: nil,
-                        services: members,
-                        origin: .inferred
+            for (candidate, members) in byCandidate {
+                if members.count >= 2 {
+                    stacks.append(
+                        Stack(projectName: candidate, composeFilePath: nil, services: members, origin: .inferred)
                     )
-                )
-            } else {
-                standalone.append(contentsOf: members)
+                } else {
+                    standalone.append(contentsOf: members)
+                }
             }
+        } else {
+            standalone = remaining
         }
 
         // Stable ordering: stacks by name, standalone by name.

ConsaiCore/Tests/ConsaiCoreTests/ProjectRegistryTests.swift

@@ -33,10 +33,10 @@ import Foundation
         #expect(result.standalone.count == 1)
     }
 
-    @Test func infersStackFromSharedPrefixWhenTwoOrMore() {
+    @Test func infersStackFromSharedPrefixWhenOptedIn() {
         let result = ProjectRegistry().assemble(containers: [
             c("1", "shop-web"), c("2", "shop-db"), c("3", "shop-cache"),
-        ])
+        ], inferStacks: true)
         #expect(result.stacks.count == 1)
         let stack = try! #require(result.stacks.first)
         #expect(stack.projectName == "shop")
@@ -46,6 +46,15 @@ import Foundation
         #expect(result.standalone.isEmpty)
     }
 
+    @Test func doesNotInferStacksByDefault() {
+        // Default (inference off): unrelated containers sharing a prefix stay standalone (#12).
+        let result = ProjectRegistry().assemble(containers: [
+            c("1", "qa-web"), c("2", "qa-cache"),
+        ])
+        #expect(result.stacks.isEmpty)
+        #expect(result.standalone.map(\.name).sorted() == ["qa-cache", "qa-web"])
+    }
+
     @Test func singleHyphenatedContainerIsNotAStack() {
         let result = ProjectRegistry().assemble(containers: [c("1", "alone-web")])
         #expect(result.stacks.isEmpty)