Reuse local iOS builds and cancel superseded PR checks

.github/workflows/android.yml

@@ -5,7 +5,22 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
+  tooling:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Check harness regressions
+        run: python3 -m unittest discover -s scripts/tests
+
   build:
     runs-on: ubuntu-24.04
     steps:
@@ -37,10 +52,9 @@ jobs:
             packages/splatkit-android/src/main/cpp/tests/WorldFrameCompletionTest.cpp \
             -o build/native-contracts/world-frame-completion
           build/native-contracts/world-frame-completion
-      - name: Check harness regressions
-        run: python3 -m unittest discover -s scripts/tests
       - name: Keep the AAR
         uses: actions/upload-artifact@v4
         with:
           name: splatkit-android-release
           path: packages/splatkit-android/build/outputs/aar/*.aar
+          retention-days: 14

.github/workflows/core.yml

@@ -5,6 +5,11 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   test:
     runs-on: ubuntu-24.04

.github/workflows/engine.yml

@@ -5,6 +5,11 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   test:
     runs-on: ubuntu-24.04

.github/workflows/ios.yml

@@ -5,6 +5,11 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   # The Metal code and its tests build on macOS; the device library is the same source
   # with the iOS toolchain flags, built here to keep it compiling.

.github/workflows/lint.yml

@@ -5,6 +5,11 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   cpp:
     runs-on: ubuntu-24.04

.github/workflows/rn-contract.yml

@@ -5,6 +5,11 @@ on:
     branches: [main]
   pull_request:
 
+# Cancel superseded PR checks; preserve each main commit for the release and mirror gates.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   contract:
     runs-on: ubuntu-24.04

AGENTS.md

@@ -4,3 +4,8 @@ SDK integration or verification: read [the harness](docs/AGENT_HARNESS.md).
 Implementation: follow [CONTRIBUTING.md](CONTRIBUTING.md); terminology lives in [CONTEXT.md](CONTEXT.md).
 Keep documentation terse; link code/contracts instead of duplicating them.
 Report skipped checks, approximation limits and emulator/physical-device provenance explicitly.
+
+Build storage: reuse ignored build directories in this checkout across sessions and reference large fixtures by path.
+Reserve session scratchpads for small disposable probes.
+React Native iOS: use the [example scripts](apps/react-native/package.json); serialize builds sharing Derived Data.
+Separate build directories are for concurrent builds or required clean-build verification.

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

apps/react-native/README.md

@@ -67,6 +67,11 @@ Restart the app after copying a world.
 The collider is optional: without one the world still renders and looks around, and the thumb stick stays hidden.
 The status line shows the load, drawn splats and GPU time, or why the world failed to load.
 
+The iOS scripts reuse `ios/build/dd` across sessions and build only the active architecture for local runs.
+`npm run ios:build` compiles without launching; pass `--mode Debug` when needed.
+Serialize builds sharing this directory; use a separate `--buildFolder` for concurrent or clean-build verification.
+Distribution builds use the standard Xcode architecture settings.
+
 ## Camera verification
 
 On a loaded world, compare `Fly route` with and without a deliberate JS-thread stall in a debug build.

apps/react-native/package.json

@@ -4,7 +4,8 @@
   "private": true,
   "scripts": {
     "android": "react-native run-android --mode release",
-    "ios": "react-native run-ios --mode Release",
+    "ios": "react-native run-ios --mode Release --buildFolder build/dd --extra-params ONLY_ACTIVE_ARCH=YES",
+    "ios:build": "react-native build-ios --mode Release --buildFolder build/dd --extra-params ONLY_ACTIVE_ARCH=YES",
     "lint": "eslint .",
     "typecheck": "tsc --noEmit",
     "start": "react-native start"

packages/react-native-splatkit/distribution/.github/workflows/contract.yml

@@ -5,6 +5,10 @@ on:
     branches: [main]
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
 jobs:
   contract:
     runs-on: ubuntu-24.04