diff --git a/.github/actions/setup-odrcore/action.yml b/.github/actions/setup-odrcore/action.yml
new file mode 100644
index 0000000..9cb0544
--- /dev/null
+++ b/.github/actions/setup-odrcore/action.yml
@@ -0,0 +1,100 @@
+name: setup odrcore
+description: >
+  Installs the toolchain and resolves odrcore and its dependencies with conan,
+  leaving the generated xcconfigs in conan-output and the runtime assets in
+  conan-assets. Every job that compiles the app needs the exact same ten steps,
+  so they live here instead of being copied into each workflow.
+
+inputs:
+  xcode-version:
+    description: Xcode version to select on the runner
+    required: true
+  profile:
+    description: conan host profile under conan/profiles
+    required: true
+  configuration:
+    description: Xcode configuration to resolve the dependencies for
+    required: true
+  cache-flavor:
+    description: >
+      Cache namespace. The simulator and the device slice resolve a different
+      dependency set, so they must not overwrite each other's cache entry.
+    required: true
+  save-cache:
+    description: >
+      Whether this job may write the conan cache back. Jobs that only consume
+      what another job built restore without saving.
+    required: false
+    default: "true"
+
+outputs:
+  conan-cache-key:
+    description: Cache key of the conan package cache, to restore it elsewhere
+    value: ${{ steps.conan-cache-key.outputs.key }}
+
+runs:
+  using: composite
+  steps:
+    - name: checkout conan-odr-index
+      shell: bash
+      run: git submodule update --init --depth 1 conan-odr-index
+
+    # 3.12+ is required by the conan-odr-index helper scripts
+    - uses: actions/setup-python@v7
+      with:
+        python-version: "3.12"
+
+    - uses: maxim-lobanov/setup-xcode@v1
+      with:
+        xcode-version: ${{ inputs.xcode-version }}
+
+    # conan itself is pinned by conan-odr-index so recipes and client stay in sync
+    - name: install conan
+      shell: bash
+      run: pip3 install -r conan-odr-index/requirements.txt
+
+    - name: conan profile
+      shell: bash
+      run: conan profile detect
+
+    - name: conan cache key
+      id: conan-cache-key
+      shell: bash
+      run: echo "key=conan2-${{ runner.os }}-xcode${{ inputs.xcode-version }}-${{ inputs.cache-flavor }}-index$(git rev-parse HEAD:conan-odr-index)-${{ hashFiles('conan/conanfile.py', 'conan/profiles/*') }}" >> "$GITHUB_OUTPUT"
+
+    # restore before exporting the recipes: the export must run on top of the
+    # restored cache so current recipes win over stale ones from the archive
+    - name: conan cache
+      if: inputs.save-cache == 'true'
+      uses: actions/cache@v6
+      with:
+        path: ~/.conan2/p
+        key: ${{ steps.conan-cache-key.outputs.key }}
+        restore-keys: |
+          conan2-${{ runner.os }}-xcode${{ inputs.xcode-version }}-${{ inputs.cache-flavor }}-
+
+    - name: restore conan cache
+      if: inputs.save-cache != 'true'
+      uses: actions/cache/restore@v6
+      with:
+        path: ~/.conan2/p
+        key: ${{ steps.conan-cache-key.outputs.key }}
+        restore-keys: |
+          conan2-${{ runner.os }}-xcode${{ inputs.xcode-version }}-${{ inputs.cache-flavor }}-
+
+    # recipes are exported from the submodule into the local cache, which is
+    # why no private remote has to be configured
+    - name: export conan-odr-index
+      shell: bash
+      run: python3 conan-odr-index/scripts/conan_export_all_packages.py
+
+    - name: conan install
+      shell: bash
+      run: >
+        conan install conan/
+        --output-folder=conan-output
+        --build=missing
+        --profile:host=conan/profiles/${{ inputs.profile }}
+        --deployer=conan/conandeployer.py
+        --deployer-folder=conan-assets
+        -o "configuration=${{ inputs.configuration }}"
diff --git a/.github/workflows/build_test.yml b/.github/workflows/build_test.yml
new file mode 100644
index 0000000..a70080c
--- /dev/null
+++ b/.github/workflows/build_test.yml
@@ -0,0 +1,97 @@
+name: build_test
+
+on:
+  workflow_dispatch:
+  # branch pushes are covered by the pull_request trigger, so only main is built
+  # directly - otherwise every push to a branch with an open PR builds twice
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - '**/*.md'
+      - 'fastlane/metadata/**'
+  pull_request:
+    paths-ignore:
+      - '**/*.md'
+      - 'fastlane/metadata/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  # the runner image only ships the iOS platform bundle for its default Xcode;
+  # older ones fail in ibtool with "iOS 26.0 Platform Not Installed"
+  xcode_version: "26.5"
+
+jobs:
+  test:
+    runs-on: macos-26
+    steps:
+      - name: checkout
+        uses: actions/checkout@v7
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+
+      - uses: ./.github/actions/setup-odrcore
+        with:
+          xcode-version: ${{ env.xcode_version }}
+          profile: ios-simulator-arm64
+          configuration: Debug
+          cache-flavor: simulator
+
+      - name: run tests
+        run: bundle exec fastlane tests
+
+      # drop temporary download/source/build folders so only built packages get cached
+      - name: clean conan cache
+        run: conan cache clean "*"
+
+      - uses: actions/upload-artifact@v7
+        if: always()
+        with:
+          name: logs
+          path: |
+            /Users/runner/Library/Developer/Xcode/DerivedData/OpenDocumentReader-*/
+
+  # the test job only ever builds the simulator slice of one configuration, so
+  # release-only and device-only breakage used to surface at deploy time
+  build:
+    runs-on: macos-26
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { scheme: "ODR Full", configuration: "Release" }
+          - { scheme: "ODR Lite", configuration: "Release Lite" }
+    steps:
+      - name: checkout
+        uses: actions/checkout@v7
+
+      - uses: ./.github/actions/setup-odrcore
+        with:
+          xcode-version: ${{ env.xcode_version }}
+          profile: ios
+          configuration: ${{ matrix.configuration }}
+          cache-flavor: device
+
+      # signing needs secrets this workflow does not have, so this only proves
+      # that the device slice compiles and links
+      - name: build
+        run: >
+          xcodebuild
+          -project OpenDocumentReader.xcodeproj
+          -scheme "${{ matrix.scheme }}"
+          -configuration "${{ matrix.configuration }}"
+          -sdk iphoneos
+          -destination 'generic/platform=iOS'
+          CODE_SIGNING_ALLOWED=NO
+          build
+
+      - name: clean conan cache
+        run: conan cache clean "*"
diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
new file mode 100644
index 0000000..f93eb21
--- /dev/null
+++ b/.github/workflows/format.yml
@@ -0,0 +1,39 @@
+name: format
+
+# swift-format comes with the Xcode toolchain, so this needs neither conan nor
+# ruby and reports style breakage in a minute instead of after a full build.
+# Unlike build_test this has no paths-ignore: every file the formatter touches
+# gets checked.
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  # the runner image only ships the iOS platform bundle for its default Xcode;
+  # older ones fail in ibtool with "iOS 26.0 Platform Not Installed"
+  xcode_version: "26.5"
+
+jobs:
+  swift-format:
+    runs-on: macos-26
+    steps:
+      - name: checkout
+        uses: actions/checkout@v7
+
+      - uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: ${{ env.xcode_version }}
+
+      - name: check formatting
+        run: scripts/format.sh --check
diff --git a/.github/workflows/ios_main.yml b/.github/workflows/ios_main.yml
deleted file mode 100644
index 5e140b2..0000000
--- a/.github/workflows/ios_main.yml
+++ /dev/null
@@ -1,181 +0,0 @@
-name: OpenDocumentReader-iOS
-
-on:
-  workflow_dispatch:
-  push:
-    branches:
-      - main
-  pull_request:
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
-env:
-  # the runner image only ships the iOS platform bundle for its default Xcode;
-  # older ones fail in ibtool with "iOS 26.0 Platform Not Installed"
-  xcode_version: "26.5"
-
-jobs:
-  # swift-format comes with the toolchain, so this needs neither conan nor ruby
-  # and reports style breakage in a minute instead of after a full build
-  format:
-    runs-on: macos-26
-    steps:
-      - name: checkout
-        uses: actions/checkout@v7
-
-      - uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: ${{ env.xcode_version }}
-
-      - name: check formatting
-        run: scripts/format.sh --check
-
-  test:
-    runs-on: macos-26
-    steps:
-      - name: checkout
-        uses: actions/checkout@v7
-
-      - name: checkout conan-odr-index
-        run: git submodule update --init --depth 1 conan-odr-index
-
-      # 3.12+ is required by the conan-odr-index helper scripts
-      - uses: actions/setup-python@v7
-        with:
-          python-version: "3.12"
-
-      - uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: ${{ env.xcode_version }}
-
-      - uses: ruby/setup-ruby@v1
-        with:
-          bundler-cache: true
-
-      # conan itself is pinned by conan-odr-index so recipes and client stay in sync
-      - name: install conan
-        run: pip3 install -r conan-odr-index/requirements.txt
-
-      - name: conan profile
-        run: conan profile detect
-
-      - name: conan cache key
-        id: conan-cache-key
-        run: echo "key=conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-simulator-index$(git rev-parse HEAD:conan-odr-index)-${{ hashFiles('conan/conanfile.py', 'conan/profiles/*') }}" >> "$GITHUB_OUTPUT"
-
-      # restore before exporting the recipes: the export must run on top of the
-      # restored cache so current recipes win over stale ones from the archive
-      - name: conan cache
-        uses: actions/cache@v6
-        with:
-          path: ~/.conan2/p
-          key: ${{ steps.conan-cache-key.outputs.key }}
-          restore-keys: |
-            conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-simulator-
-
-      # recipes are exported from the submodule into the local cache, which is
-      # why no private remote has to be configured
-      - name: export conan-odr-index
-        run: python3 conan-odr-index/scripts/conan_export_all_packages.py
-
-      - name: conan install
-        run: >
-          conan install conan/
-          --output-folder=conan-output
-          --build=missing
-          --profile:host=conan/profiles/ios-simulator-arm64
-          --deployer=conan/conandeployer.py
-          --deployer-folder=conan-assets
-          -o "configuration=Debug"
-
-      - name: run tests
-        run: bundle exec fastlane tests
-
-      # drop temporary download/source/build folders so only built packages get cached
-      - name: clean conan cache
-        run: conan cache clean "*"
-
-      - uses: actions/upload-artifact@v7
-        if: always()
-        with:
-          name: logs
-          path: |
-            /Users/runner/Library/Developer/Xcode/DerivedData/OpenDocumentReader-*/
-
-  # the test job only ever builds the simulator slice of one configuration, so
-  # release-only and device-only breakage used to surface at deploy time
-  build:
-    runs-on: macos-26
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - { scheme: "ODR Full", configuration: "Release" }
-          - { scheme: "ODR Lite", configuration: "Release Lite" }
-    steps:
-      - name: checkout
-        uses: actions/checkout@v7
-
-      - name: checkout conan-odr-index
-        run: git submodule update --init --depth 1 conan-odr-index
-
-      - uses: actions/setup-python@v7
-        with:
-          python-version: "3.12"
-
-      - uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: ${{ env.xcode_version }}
-
-      - uses: ruby/setup-ruby@v1
-        with:
-          bundler-cache: true
-
-      - name: install conan
-        run: pip3 install -r conan-odr-index/requirements.txt
-
-      - name: conan profile
-        run: conan profile detect
-
-      - name: conan cache key
-        id: conan-cache-key
-        run: echo "key=conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-device-index$(git rev-parse HEAD:conan-odr-index)-${{ hashFiles('conan/conanfile.py', 'conan/profiles/*') }}" >> "$GITHUB_OUTPUT"
-
-      - name: conan cache
-        uses: actions/cache@v6
-        with:
-          path: ~/.conan2/p
-          key: ${{ steps.conan-cache-key.outputs.key }}
-          restore-keys: |
-            conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-device-
-
-      - name: export conan-odr-index
-        run: python3 conan-odr-index/scripts/conan_export_all_packages.py
-
-      - name: conan install
-        run: >
-          conan install conan/
-          --output-folder=conan-output
-          --build=missing
-          --profile:host=conan/profiles/ios
-          --deployer=conan/conandeployer.py
-          --deployer-folder=conan-assets
-          -o "configuration=${{ matrix.configuration }}"
-
-      # signing needs secrets this workflow does not have, so this only proves
-      # that the device slice compiles and links
-      - name: build
-        run: >
-          xcodebuild
-          -project OpenDocumentReader.xcodeproj
-          -scheme "${{ matrix.scheme }}"
-          -configuration "${{ matrix.configuration }}"
-          -sdk iphoneos
-          -destination 'generic/platform=iOS'
-          CODE_SIGNING_ALLOWED=NO
-          build
-
-      - name: clean conan cache
-        run: conan cache clean "*"
diff --git a/.github/workflows/ios_release.yml b/.github/workflows/release.yml
similarity index 68%
rename from .github/workflows/ios_release.yml
rename to .github/workflows/release.yml
index f15ba24..85baca9 100644
--- a/.github/workflows/ios_release.yml
+++ b/.github/workflows/release.yml
@@ -1,4 +1,4 @@
-name: OpenDocumentReader-iOS-release
+name: release
 
 # Manual only. Releasing stays a deliberate act, this just moves it off
 # whoever's laptop happened to have the Apple ID signed in.
@@ -18,6 +18,9 @@ concurrency:
   group: ${{ github.workflow }}
   cancel-in-progress: false
 
+permissions:
+  contents: read
+
 env:
   xcode_version: "26.5"
 
@@ -48,53 +51,21 @@ jobs:
           fi
 
       - name: checkout
-        uses: actions/checkout@v4
-
-      - name: checkout conan-odr-index
-        run: git submodule update --init --depth 1 conan-odr-index
-
-      - uses: actions/setup-python@v5
-        with:
-          python-version: "3.12"
-
-      - uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: ${{ env.xcode_version }}
+        uses: actions/checkout@v7
 
       - uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
 
-      - name: install conan
-        run: pip3 install -r conan-odr-index/requirements.txt
-
-      - name: conan profile
-        run: conan profile detect
-
-      - name: conan cache key
-        id: conan-cache-key
-        run: echo "key=conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-device-index$(git rev-parse HEAD:conan-odr-index)-${{ hashFiles('conan/conanfile.py', 'conan/profiles/*') }}" >> "$GITHUB_OUTPUT"
-
-      - name: conan cache
-        uses: actions/cache/restore@v4
+      # a release consumes what build_test already built and never writes the
+      # cache back, so an untested release cannot poison it
+      - uses: ./.github/actions/setup-odrcore
         with:
-          path: ~/.conan2/p
-          key: ${{ steps.conan-cache-key.outputs.key }}
-          restore-keys: |
-            conan2-${{ runner.os }}-xcode${{ env.xcode_version }}-device-
-
-      - name: export conan-odr-index
-        run: python3 conan-odr-index/scripts/conan_export_all_packages.py
-
-      - name: conan install
-        run: >
-          conan install conan/
-          --output-folder=conan-output
-          --build=missing
-          --profile:host=conan/profiles/ios
-          --deployer=conan/conandeployer.py
-          --deployer-folder=conan-assets
-          -o "configuration=${{ matrix.flavor == 'pro' && 'Release' || 'Release Lite' }}"
+          xcode-version: ${{ env.xcode_version }}
+          profile: ios
+          configuration: ${{ matrix.flavor == 'pro' && 'Release' || 'Release Lite' }}
+          cache-flavor: device
+          save-cache: "false"
 
       # a throwaway keychain so the distribution certificate never outlives the job
       - name: import signing certificate
@@ -127,7 +98,7 @@ jobs:
           ASC_KEY_CONTENT: ${{ secrets.ASC_KEY_CONTENT }}
         run: bundle exec fastlane ${{ matrix.flavor == 'pro' && 'deployPro' || 'deployLite' }}
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v7
         if: always()
         with:
           name: build-log-${{ matrix.flavor }}
diff --git a/README.md b/README.md
index 0dcc515..38e894b 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# OpenDocument.ios ![](https://github.com/opendocument-app/OpenDocument.ios/actions/workflows/ios_main.yml/badge.svg)
+# OpenDocument.ios ![](https://github.com/opendocument-app/OpenDocument.ios/actions/workflows/build_test.yml/badge.svg) ![](https://github.com/opendocument-app/OpenDocument.ios/actions/workflows/format.yml/badge.svg)
 It's Android's first OpenOffice Document Reader... for iOS!
 
 This is an iOS frontend for our C++ [OpenDocument.core](https://github.com/opendocument-app/OpenDocument.core) library.
@@ -32,10 +32,23 @@ Swift sources are formatted with `swift-format` from the active Xcode
 toolchain, configured in `.swift-format`. Run `scripts/format.sh` before
 committing; CI runs `scripts/format.sh --check` and fails on any difference.
 
+## Continuous integration
+
+| workflow | what it does |
+| --- | --- |
+| `format` | `scripts/format.sh --check`, on every push and pull request |
+| `build_test` | unit tests on the simulator plus a device build of both flavors |
+| `release` | manual upload to App Store Connect, see below |
+
+`format` needs nothing but the Xcode toolchain and reports style breakage in a
+minute, so it is kept apart from the native build. Everything that does need
+odrcore shares `.github/actions/setup-odrcore`, which resolves the C++
+dependencies with conan and caches them per Xcode version and profile.
+
 ## Releasing
 
-The `OpenDocumentReader-iOS-release` workflow uploads a build to App Store
-Connect. It is manual (`workflow_dispatch`) and never submits for review, so
+The `release` workflow uploads a build to App Store Connect. It is manual
+(`workflow_dispatch`) and never submits for review, so
 promoting a build stays a deliberate step in App Store Connect. Build numbers
 come from whatever TestFlight already has, so nothing needs to be committed to
 cut a release.