iOS build: fix the hot spots that made CI time out, and fail fast on the next one

.github/workflows/ci.yml

@@ -510,9 +510,20 @@ jobs:
     # Here it held three of the account's five macOS runners at a time.
     name: Swift tests + iOS build
     runs-on: macos-latest
-    timeout-minutes: 30
+    # About five minutes end to end: package tests ~1.5, xcodegen ~1, the
+    # simulator build ~2. The cap is a hang guard, not room for the build
+    # to grow into: the two guard steps below name the slow code instead.
+    timeout-minutes: 15
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: No #available branch in a View extension
+        # The way the Oct 2026 build went from 5 to 25+ minutes: a
+        # `@ViewBuilder` View extension branching on `#available` doubles the
+        # caller's view type at every call, and IRGen on the batch holding
+        # both never finishes. The type-check flag below cannot see it and a
+        # build killed at the cap prints nothing, so the shape is refused at
+        # the source: such a shim is a ViewModifier (ios/App/BackDeployCompat.swift).
+        run: bash scripts/check-ios-view-shims.sh
       - name: Swift package tests
         run: swift test --package-path ios
       - name: Generate the Xcode project
@@ -521,15 +532,53 @@ jobs:
           cd ios
           xcodegen generate
       - name: Build the simulator app
+        # One slice. The generic simulator destination builds arm64 AND
+        # x86_64 (ONLY_ACTIVE_ARCH is a no-op there), and nothing runs the
+        # x86_64 one: the runner, the UI-test simulators and every current
+        # Mac are arm64. Two slices doubled the compile and ran six
+        # swift-frontends side by side on a 3-core, 7 GB runner. The log is
+        # kept for the type-check step that follows.
         run: |
+          set -o pipefail
           cd ios
           xcodebuild \
             -project OpenMausCompanion.xcodeproj \
             -scheme OpenMausCompanion \
             -sdk iphonesimulator \
             -destination 'generic/platform=iOS Simulator' \
+            ARCHS=arm64 \
             CODE_SIGNING_ALLOWED=NO \
-            build
+            build | tee "$RUNNER_TEMP/xcodebuild.log"
+      - name: No Swift expression or body over the type-check limit
+        # ios/project.yml (Debug) has the compiler warn when it spends more
+        # than 500 ms type-checking one expression or function body, the
+        # usual way a SwiftUI build turns from minutes into a timeout. Swift
+        # has no diagnostic group for those two warnings, so -Werror cannot
+        # single them out; the log is read instead.
+        #
+        # 500 ms is the bar on a developer Mac, where Xcode shows the
+        # warning at its line. It is not a stable verdict on this runner:
+        # the compiler measures wall-clock time, and the shared 3-core
+        # runner swings about 2x from one run to the next (bodies at 216
+        # and 263 ms on an M5 measured 551 and 600 ms here on a loaded run,
+        # under 420 ms on a quiet one). The step therefore lists every
+        # body over the 500 ms warning limit, and fails only on one over
+        # three times that, which no body in the app comes near and which
+        # a type-check problem on its way to a timeout runs past.
+        run: |
+          fail_over_ms=1500
+          warnings=$(grep -E 'took [0-9]+ms to type-check \(limit: ' "$RUNNER_TEMP/xcodebuild.log" | sed -E 's#^.*/ios/##' | sort -u || true)
+          if [ -n "$warnings" ]; then
+            echo "Over the 500 ms warning limit on this runner (fails at ${fail_over_ms} ms):"
+            printf '%s\n' "$warnings"
+          fi
+          hits=$(printf '%s\n' "$warnings" | awk -v limit="$fail_over_ms" 'match($0, /took [0-9]+ms/) { ms = substr($0, RSTART + 5, RLENGTH - 7) + 0; if (ms > limit) print }')
+          if [ -n "$hits" ]; then
+            printf '%s\n' "$hits"
+            echo "::error::The Swift type checker spent over ${fail_over_ms} ms on the expression(s) above. Split that body into smaller views or functions, and give colours chosen by a ternary an explicit Color type."
+            exit 1
+          fi
+          echo "No expression or function body took the type checker over ${fail_over_ms} ms."
 
   # Selection includes ios/** as well as android/**: :core's fixtures come
   # from ios/Tests/CompanionCoreTests/Fixtures.

ios/App/ActivityRunChip.swift

@@ -23,53 +23,64 @@ struct ActivityRunChip: View {
         running ? "Running \(items.count) steps" : "Ran \(items.count) steps"
     }
 
-    var body: some View {
-        let isDark = colorScheme == .dark
+    private var isDark: Bool { colorScheme == .dark }
+    private var chipFill: Color { isDark ? Color.white.opacity(0.08) : Color.black.opacity(0.05) }
+    private var chipStroke: Color { isDark ? Color.white.opacity(0.08) : Color.black.opacity(0.06) }
+    private var summaryColor: Color { isDark ? Color(hex: "#E2E8F0") : Color(hex: "#334155") }
 
+    var body: some View {
         VStack(alignment: .leading, spacing: 6) {
-            Button {
-                withAnimation(.spring(response: 0.3, dampingFraction: 0.75)) { expanded.toggle() }
-                Haptics.selection()
-            } label: {
-                HStack(spacing: 6) {
-                    Image(systemName: running ? "ellipsis.circle" : "checkmark.seal.fill")
-                        .font(.system(size: 11))
-                        .foregroundColor(running ? Color.secondary : Color(hex: "#22C55E"))
+            summaryButton
+            if expanded {
+                unfoldedSteps
+            }
+        }
+        .padding(.leading, 2)
+    }
+
+    private var summaryButton: some View {
+        Button {
+            withAnimation(.spring(response: 0.3, dampingFraction: 0.75)) { expanded.toggle() }
+            Haptics.selection()
+        } label: {
+            summaryLabel
+        }
+        .buttonStyle(.plain)
+        .accessibilityLabel(summary)
+        .accessibilityHint(expanded ? "Hides the steps" : "Shows the steps")
+    }
 
-                    Text(summary)
-                        .font(.caption2.weight(.bold))
-                        .foregroundColor(isDark ? Color(hex: "#E2E8F0") : Color(hex: "#334155"))
+    private var summaryLabel: some View {
+        HStack(spacing: 6) {
+            Image(systemName: running ? "ellipsis.circle" : "checkmark.seal.fill")
+                .font(.system(size: 11))
+                .foregroundColor(running ? Color.secondary : Color(hex: "#22C55E"))
 
-                    Image(systemName: "chevron.right")
-                        .font(.system(size: 8, weight: .bold))
-                        .foregroundColor(Color.secondary)
-                        .rotationEffect(.degrees(expanded ? 90 : 0))
-                }
-                .padding(.horizontal, 9)
-                .padding(.vertical, 4.5)
-                .background(isDark ? Color.white.opacity(0.08) : Color.black.opacity(0.05))
-                .clipShape(Capsule())
-                .overlay(
-                    Capsule()
-                        .stroke(isDark ? Color.white.opacity(0.08) : Color.black.opacity(0.06), lineWidth: 0.5)
-                )
-            }
-            .buttonStyle(.plain)
-            .accessibilityLabel(summary)
-            .accessibilityHint(expanded ? "Hides the steps" : "Shows the steps")
+            Text(summary)
+                .font(.caption2.weight(.bold))
+                .foregroundColor(summaryColor)
 
-            if expanded {
-                VStack(alignment: .leading, spacing: 4) {
-                    ForEach(items, id: \.id) { item in
-                        ActivityChip(
-                            tool: item.tool, threadRef: item.threadRef, openThread: openThread,
-                            outputIsProse: item.isTeammateReport
-                        )
-                    }
-                }
-                .transition(.opacity.combined(with: .move(edge: .top)))
+            Image(systemName: "chevron.right")
+                .font(.system(size: 8, weight: .bold))
+                .foregroundColor(Color.secondary)
+                .rotationEffect(.degrees(expanded ? 90 : 0))
+        }
+        .padding(.horizontal, 9)
+        .padding(.vertical, 4.5)
+        .background(chipFill)
+        .clipShape(Capsule())
+        .overlay(Capsule().stroke(chipStroke, lineWidth: 0.5))
+    }
+
+    private var unfoldedSteps: some View {
+        VStack(alignment: .leading, spacing: 4) {
+            ForEach(items, id: \.id) { item in
+                ActivityChip(
+                    tool: item.tool, threadRef: item.threadRef, openThread: openThread,
+                    outputIsProse: item.isTeammateReport
+                )
             }
         }
-        .padding(.leading, 2)
+        .transition(.opacity.combined(with: .move(edge: .top)))
     }
 }