.github/workflows: Migrate workflows to Blacksmith runners

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
   bun:
     if: github.repository == 'athasdev/athas'
     name: Bun — typecheck, frontend check
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     steps:
       - uses: actions/checkout@v4
 
@@ -41,7 +41,7 @@ jobs:
   rust:
     if: github.repository == 'athasdev/athas'
     name: Rust — fmt, cargo check
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     env:
       CARGO_TERM_COLOR: always
     steps:

.github/workflows/nix.yml

@@ -21,7 +21,7 @@ on:
 jobs:
   dev-shell:
     name: Dev shell
-    runs-on: ubuntu-24.04
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -34,7 +34,7 @@ jobs:
 
       - name: Validate dev tools
         run: |
-          nix develop --no-write-lock-file --command bash -lc '
+          nix develop --no-write-lock-file --command bash -c '
             bun --version
             node --version
             rustc --version

.github/workflows/release-preflight.yml

@@ -9,7 +9,7 @@ concurrency:
 
 jobs:
   readiness:
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     permissions:
       contents: read
     steps:
@@ -65,7 +65,7 @@ jobs:
           bun scripts/check-zig.ts
 
   macos-readiness:
-    runs-on: macos-latest
+    runs-on: blacksmith-6vcpu-macos-15
     steps:
       - uses: actions/checkout@v6
 
@@ -114,7 +114,7 @@ jobs:
             >/dev/null
 
   windows-readiness:
-    runs-on: windows-latest
+    runs-on: blacksmith-4vcpu-windows-2025
     steps:
       - uses: actions/checkout@v6
 

.github/workflows/release.yml

@@ -17,7 +17,7 @@ concurrency:
 
 jobs:
   release-metadata:
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     permissions:
       contents: read
     if: ${{ startsWith(github.ref, 'refs/tags/v') || github.event_name == 'workflow_dispatch' }}
@@ -84,7 +84,7 @@ jobs:
       matrix:
         include:
           - platform: "macos-latest"
-            artifact: "macos-aarch64"
+            artifact: "blacksmith-6vcpu-macos-15"
             os: "macos"
             args: "--target aarch64-apple-darwin"
             cargo_features: ""
@@ -394,7 +394,7 @@ jobs:
 
   assemble-release:
     needs: [release-metadata, build-tauri]
-    runs-on: ubuntu-latest
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     permissions:
       contents: write
     if: ${{ success() && (startsWith(github.ref, 'refs/tags/v') || github.event_name == 'workflow_dispatch') }}