diff --git a/.github/actionlint.yaml b/.github/actionlint.yaml
new file mode 100644
index 000000000000..c4d5692a9d9a
--- /dev/null
+++ b/.github/actionlint.yaml
@@ -0,0 +1,7 @@
+self-hosted-runner:
+  labels:
+    - blacksmith-6vcpu-macos-15
+    - blacksmith-6vcpu-macos-26
+    - blacksmith-6vcpu-macos-latest
+
+config-variables: null
diff --git a/.github/workflows/build-ghosttykit.yml b/.github/workflows/build-ghosttykit.yml
index 109ed364690b..8a9ffd697c44 100644
--- a/.github/workflows/build-ghosttykit.yml
+++ b/.github/workflows/build-ghosttykit.yml
@@ -9,7 +9,7 @@ concurrency:
 
 jobs:
   build-ghosttykit:
-    runs-on: warp-macos-15-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 20
     env:
       GHOSTTYKIT_CRASH_REPORT_SUBDIR: cmux/crash
diff --git a/.github/workflows/ci-macos-compat.yml b/.github/workflows/ci-macos-compat.yml
index 61f98c5e3d83..0e451b6c98e6 100644
--- a/.github/workflows/ci-macos-compat.yml
+++ b/.github/workflows/ci-macos-compat.yml
@@ -9,12 +9,12 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - os: warp-macos-15-arm64-6x
+          - os: blacksmith-6vcpu-macos-15
             timeout: 30
             startup_smoke: true
             virtual_display: true
             skip_zig: false
-          - os: warp-macos-26-arm64-6x
+          - os: blacksmith-6vcpu-macos-26
             timeout: 30
             startup_smoke: true
             virtual_display: false
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a75b9b0a42d2..a61d61723ba8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -158,7 +158,7 @@ jobs:
           bun test tests/vm-db-read-model.test.ts
 
   tests:
-    runs-on: warp-macos-15-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 75
     env:
       CMUX_SKIP_ZIG_BUILD: "1"
@@ -380,7 +380,7 @@ jobs:
     # Keep lag validation separate from UI regressions so functional UI failures
     # and performance regressions stay isolated. Broader interactive UI suites
     # still run via test-e2e.yml on GitHub-hosted runners.
-    runs-on: warp-macos-15-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 20
     steps:
       - name: Checkout
@@ -568,7 +568,7 @@ jobs:
     # Compile the same unsigned universal Release app that nightly builds before
     # signing, notarization, and publishing. This catches DEBUG/Release boundary
     # mistakes before they reach main.
-    runs-on: warp-macos-26-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-26
     timeout-minutes: 20
     steps:
       - name: Checkout
@@ -653,7 +653,7 @@ jobs:
             CODE_SIGNING_ALLOWED=NO ASSETCATALOG_COMPILER_APPICON_NAME=AppIcon-Nightly build
 
   ui-regressions:
-    runs-on: warp-macos-15-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 25
     steps:
       - name: Checkout
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 700825a43565..8bba32fecafb 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -100,7 +100,7 @@ jobs:
   build-sign-notarize-nightly:
     needs: decide
     if: needs.decide.outputs.should_build == 'true'
-    runs-on: warp-macos-26-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-26
     timeout-minutes: 20
     steps:
       - name: Checkout build ref
diff --git a/.github/workflows/perf-activation.yml b/.github/workflows/perf-activation.yml
index fd2967833239..00ddd8410b35 100644
--- a/.github/workflows/perf-activation.yml
+++ b/.github/workflows/perf-activation.yml
@@ -11,11 +11,12 @@ on:
       runner:
         description: macOS runner
         required: false
-        default: warp-macos-15-arm64-6x
+        default: blacksmith-6vcpu-macos-15
         type: choice
         options:
-          - warp-macos-15-arm64-6x
-          - depot-macos-latest
+          - blacksmith-6vcpu-macos-15
+          - blacksmith-6vcpu-macos-26
+          - blacksmith-6vcpu-macos-latest
       workspace_count:
         description: Fixture workspace count
         required: false
@@ -35,7 +36,7 @@ concurrency:
 
 jobs:
   activation-session:
-    runs-on: ${{ inputs.runner || 'warp-macos-15-arm64-6x' }}
+    runs-on: ${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}
     timeout-minutes: 45
     env:
       PERF_TAG: perfci
@@ -85,8 +86,8 @@ jobs:
         uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
           path: .ci-source-packages
-          key: spm-${{ hashFiles('cmux.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
-          restore-keys: spm-
+          key: spm-${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}-${{ hashFiles('cmux.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
+          restore-keys: spm-${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}-
 
       - name: Resolve Swift packages
         run: |
@@ -133,12 +134,17 @@ jobs:
         run: |
           set -euo pipefail
           APP_PATH="$HOME/Library/Developer/Xcode/DerivedData/cmux-$PERF_TAG/Build/Products/Debug/cmux DEV $PERF_TAG.app"
-          swift scripts/bench-window-visibility.swift \
-            "$APP_PATH" \
-            "com.cmuxterm.app.debug.$PERF_TAG" \
-            30 \
-            --cmd-tab-activation \
-            --cg-visibility \
+          # The GitHub Actions runner process runs in launchd's system
+          # bootstrap, not the console user's Aqua session, so windows
+          # created by apps launched via NSWorkspace.openApplication do
+          # not show up in CGWindowListCopyWindowInfo([.optionOnScreenOnly]).
+          # Re-enter the Aqua session via launchctl asuser before running
+          # the bench so visibility polling sees real on-screen windows.
+          CONSOLE_USER="$(stat -f %Su /dev/console)"
+          CONSOLE_UID="$(id -u "$CONSOLE_USER")"
+          sudo -n launchctl asuser "$CONSOLE_UID" sudo -n -u "$CONSOLE_USER" -E \
+            env PATH="$PATH" DEVELOPER_DIR="$DEVELOPER_DIR" \
+            bash -c "cd '$PWD' && swift scripts/bench-window-visibility.swift '$APP_PATH' 'com.cmuxterm.app.debug.$PERF_TAG' 30 --cmd-tab-activation --cg-visibility" \
             > perf-results/cmd-tab-activation.txt
           cat perf-results/cmd-tab-activation.txt
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index c842a3496972..3adfc6d47b8b 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -16,7 +16,7 @@ env:
 
 jobs:
   build-sign-notarize:
-    runs-on: warp-macos-26-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-26
     timeout-minutes: 20
     steps:
       - name: Checkout
diff --git a/.github/workflows/test-depot.yml b/.github/workflows/test-depot.yml
index d81dd94bcb9e..18b1873f709f 100644
--- a/.github/workflows/test-depot.yml
+++ b/.github/workflows/test-depot.yml
@@ -28,7 +28,7 @@ on:
 
 jobs:
   tests:
-    runs-on: warp-macos-15-arm64-6x
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 20
     steps:
       - name: Checkout
diff --git a/.github/workflows/test-e2e.yml b/.github/workflows/test-e2e.yml
index bbf8aee9c0e4..f5eb617268e4 100644
--- a/.github/workflows/test-e2e.yml
+++ b/.github/workflows/test-e2e.yml
@@ -20,17 +20,20 @@ on:
         default: true
         type: boolean
       runner:
-        description: "Runner OS (Depot runners for GUI activation support)"
+        description: "Runner OS (macOS 15 default for GUI activation support)"
         required: false
-        default: "depot-macos-latest"
+        default: "blacksmith-6vcpu-macos-15"
         type: choice
         options:
+          - blacksmith-6vcpu-macos-15
+          - blacksmith-6vcpu-macos-26
+          - blacksmith-6vcpu-macos-latest
           - depot-macos-latest
           - depot-macos-14
 
 jobs:
   e2e:
-    runs-on: ${{ inputs.runner || 'depot-macos-latest' }}
+    runs-on: ${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}
     timeout-minutes: 20
     env:
       TEST_REF: ${{ inputs.ref || github.ref }}
@@ -172,8 +175,8 @@ jobs:
         uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
           path: .ci-source-packages
-          key: spm-${{ inputs.runner || 'depot-macos-latest' }}-${{ hashFiles('cmux.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
-          restore-keys: spm-${{ inputs.runner || 'depot-macos-latest' }}-
+          key: spm-${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}-${{ hashFiles('cmux.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved') }}
+          restore-keys: spm-${{ inputs.runner || 'blacksmith-6vcpu-macos-15' }}-
 
       - name: Resolve Swift packages
         run: |
diff --git a/.github/workflows/tmux-corpus.yml b/.github/workflows/tmux-corpus.yml
index 4f193acdaf7c..b7cc29224310 100644
--- a/.github/workflows/tmux-corpus.yml
+++ b/.github/workflows/tmux-corpus.yml
@@ -57,7 +57,7 @@ jobs:
 
   terminal-nightly:
     if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
-    runs-on: [self-hosted, warp-macos-15-arm64-6x]
+    runs-on: blacksmith-6vcpu-macos-15
     timeout-minutes: 30
     steps:
       - name: Checkout
diff --git a/tests/test_ci_self_hosted_guard.sh b/tests/test_ci_self_hosted_guard.sh
index ab06f4e01f4b..d1ee974f0a09 100755
--- a/tests/test_ci_self_hosted_guard.sh
+++ b/tests/test_ci_self_hosted_guard.sh
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 # Regression test for https://github.com/manaflow-ai/cmux/issues/385.
-# Ensures paid CI jobs use WarpBuild runners.
+# Ensures paid CI jobs use Blacksmith macOS runners.
 # Fork PRs are gated by GitHub's built-in "Require approval for outside
 # collaborators" setting, so workflow-level fork guards are not needed.
 set -euo pipefail
@@ -10,29 +10,29 @@ CI_FILE="$ROOT_DIR/.github/workflows/ci.yml"
 GHOSTTYKIT_FILE="$ROOT_DIR/.github/workflows/build-ghosttykit.yml"
 COMPAT_FILE="$ROOT_DIR/.github/workflows/ci-macos-compat.yml"
 
-check_warp_runner() {
+check_blacksmith_runner() {
   local file="$1" job="$2"
   if ! awk -v job="$job" '
     $0 ~ "^  "job":" { in_job=1; next }
-    in_job && /^  [^[:space:]]/ { in_job=0 }
-    in_job && /runs-on:.*warp-macos-.*-arm64/ { saw_warp=1 }
-    in_job && /os: warp-macos-.*-arm64/ { saw_warp=1 }
-    END { exit !(saw_warp) }
+    in_job && /^  [^[:space:]#][^:]*:[[:space:]]*(#.*)?$/ { in_job=0 }
+    in_job && /runs-on:.*blacksmith-[0-9]+vcpu-macos-/ { saw=1 }
+    in_job && /os: blacksmith-[0-9]+vcpu-macos-/ { saw=1 }
+    END { exit !(saw) }
   ' "$file"; then
-    echo "FAIL: $job in $(basename "$file") must use a WarpBuild runner"
+    echo "FAIL: $job in $(basename "$file") must use the expected macOS runner"
     exit 1
   fi
-  echo "PASS: $job WarpBuild runner is present"
+  echo "PASS: $job in $(basename "$file") uses the expected macOS runner"
 }
 
 # ci.yml jobs
-check_warp_runner "$CI_FILE" "tests"
-check_warp_runner "$CI_FILE" "tests-build-and-lag"
-check_warp_runner "$CI_FILE" "release-build"
-check_warp_runner "$CI_FILE" "ui-regressions"
+check_blacksmith_runner "$CI_FILE" "tests"
+check_blacksmith_runner "$CI_FILE" "tests-build-and-lag"
+check_blacksmith_runner "$CI_FILE" "release-build"
+check_blacksmith_runner "$CI_FILE" "ui-regressions"
 
 # build-ghosttykit.yml
-check_warp_runner "$GHOSTTYKIT_FILE" "build-ghosttykit"
+check_blacksmith_runner "$GHOSTTYKIT_FILE" "build-ghosttykit"
 
-# ci-macos-compat.yml (uses matrix.os with WarpBuild runners)
-check_warp_runner "$COMPAT_FILE" "compat-tests"
+# ci-macos-compat.yml (uses matrix.os with Blacksmith runners)
+check_blacksmith_runner "$COMPAT_FILE" "compat-tests"