diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bd10a0a9..5dee6b72 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -252,7 +252,13 @@ jobs:
     name: Phase 1 real-authority conformance
     runs-on: macos-15
     needs: [web, changes]
-    if: needs.changes.outputs.docs_only != 'true'
+    # macOS bills at ten times the Linux rate and this job is the longest one
+    # here, so it runs on main and on a pull request that asks for it by
+    # carrying the `ci:full` label.
+    if: >-
+      needs.changes.outputs.docs_only != 'true'
+      && ((github.event_name == 'push' && github.ref == 'refs/heads/main')
+      || contains(github.event.pull_request.labels.*.name, 'ci:full'))
     timeout-minutes: 120
     permissions:
       contents: read
@@ -458,7 +464,15 @@ jobs:
     needs: changes
     # macOS runners bill at ten times the Linux rate. Spending that on a branch
     # that changed only prose is the least defensible minute in this file.
-    if: needs.changes.outputs.docs_only != 'true'
+    #
+    # It cannot move to Linux: it cross-builds the Windows supervisor from an
+    # arm64 Homebrew mingw-w64 bottle, pinned by digest below. So it runs on
+    # main, and on a pull request that carries the `ci:full` label -- which any
+    # branch touching src-tauri or the supervisors should.
+    if: >-
+      needs.changes.outputs.docs_only != 'true'
+      && ((github.event_name == 'push' && github.ref == 'refs/heads/main')
+      || contains(github.event.pull_request.labels.*.name, 'ci:full'))
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4.4.0
@@ -589,12 +603,16 @@ jobs:
     timeout-minutes: 15
     strategy:
       fail-fast: false
+      # linux-x64 runs everywhere. darwin-arm64 is a macOS runner, so it
+      # joins on main or under the `ci:full` label. A matrix entry cannot
+      # carry its own condition, so the include list is selected here.
       matrix:
-        include:
-          - platform: linux-x64
-            runner: ubuntu-24.04
-          - platform: darwin-arm64
-            runner: macos-14
+        include: >-
+          ${{ fromJSON(
+            ((github.event_name == 'push' && github.ref == 'refs/heads/main')
+              || contains(github.event.pull_request.labels.*.name, 'ci:full'))
+            && '[{"platform":"linux-x64","runner":"ubuntu-24.04"},{"platform":"darwin-arm64","runner":"macos-14"}]'
+            || '[{"platform":"linux-x64","runner":"ubuntu-24.04"}]') }}
     steps:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4.4.0
         with:
@@ -606,7 +624,13 @@ jobs:
     name: Windows supervisor behavior
     runs-on: windows-2025
     needs: [changes, rust]
-    if: always() && needs.rust.result == 'success' && needs.changes.outputs.docs_only != 'true'
+    # Windows bills at twice the Linux rate, and this job needs the artifact
+    # `rust` produces, so it follows the same gate.
+    if: >-
+      always() && needs.rust.result == 'success'
+      && needs.changes.outputs.docs_only != 'true'
+      && ((github.event_name == 'push' && github.ref == 'refs/heads/main')
+      || contains(github.event.pull_request.labels.*.name, 'ci:full'))
     timeout-minutes: 20
     permissions:
       contents: read
diff --git a/phase1-conformance.lock.json b/phase1-conformance.lock.json
index df41a549..d6847c61 100644
--- a/phase1-conformance.lock.json
+++ b/phase1-conformance.lock.json
@@ -141,8 +141,8 @@
       },
       {
         "path": ".github/workflows/ci.yml",
-        "blob": "bd10a0a97f7d450086319e9e644591337c574e7b",
-        "sha256": "62fe688a15e0ca7d8a244af51f3a6c87a2624e2ded8e312c2bb3590542ca6dc2"
+        "blob": "5dee6b72205f7098b832a0da6c996afad3f5874e",
+        "sha256": "c3659b47808dcde989c10c7b37efe0845c743e18b25381182748329ce1e6cc71"
       },
       {
         "path": ".github/workflows/client-v1-conformance.yml",
diff --git a/src/client-v1-conformance-workflow.test.ts b/src/client-v1-conformance-workflow.test.ts
index f4f3d3fc..96aa427d 100644
--- a/src/client-v1-conformance-workflow.test.ts
+++ b/src/client-v1-conformance-workflow.test.ts
@@ -2239,8 +2239,13 @@ describe('Chat-local protected Windows conformance workflow', () => {
     const workflow = readFileSync(resolve(projectRoot, '.github', 'workflows', 'ci.yml'), 'utf8');
     const job = workflowJob(workflow, 'unix-supervisor');
     expect(job).toContain('runs-on: $' + '{{ matrix.runner }}');
-    expect(job).toContain('runner: ubuntu-24.04');
-    expect(job).toContain('runner: macos-14');
+    // The include list is selected by expression -- linux-x64 on every branch,
+    // darwin-arm64 on main or under the `ci:full` label -- because a matrix
+    // entry cannot carry its own condition. Both platforms must still be
+    // reachable, and the macOS one must be the gated half.
+    expect(job).toContain('"platform":"linux-x64","runner":"ubuntu-24.04"');
+    expect(job).toContain('"platform":"darwin-arm64","runner":"macos-14"');
+    expect(job).toContain("contains(github.event.pull_request.labels.*.name, 'ci:full')");
     expect(job).toContain('bash scripts/unix-producer-supervisor.test.sh');
 
     const runtimeTest = readFileSync(
diff --git a/src/specification-guards.test.ts b/src/specification-guards.test.ts
index ad659378..d6ff42c3 100644
--- a/src/specification-guards.test.ts
+++ b/src/specification-guards.test.ts
@@ -1042,11 +1042,37 @@ describe('Phase 1 specification guards', () => {
     expect(workflow).toMatch(/^ {2}changes:$/m);
     expect(workflow).toContain('docs_only: $' + '{{ steps.classify.outputs.docs_only }}');
 
-    const gatedJobs = [...workflowJobs(workflow)]
-      .filter(([, job]) => /^ {4}if: needs\.changes\.outputs\.docs_only != 'true'$/m.test(job))
+    const jobs = new Map(workflowJobs(workflow));
+    const gatedJobs = [...jobs]
+      .filter(([, job]) => job.includes("needs.changes.outputs.docs_only != 'true'"))
       .map(([name]) => name);
 
-    expect(gatedJobs).toEqual(['e2e', 'phase1-conformance', 'desktop', 'rust', 'unix-supervisor']);
+    expect(gatedJobs).toEqual([
+      'e2e',
+      'phase1-conformance',
+      'desktop',
+      'rust',
+      'unix-supervisor',
+      'windows-supervisor-behavior',
+    ]);
+
+    // Prose is not the only minute worth not spending. macOS bills at ten
+    // times the Linux rate and Windows at twice it, so those runners also wait
+    // for main -- or for a pull request that asks for them by carrying the
+    // `ci:full` label, which any branch touching src-tauri or the supervisors
+    // should. `unix-supervisor` keeps linux-x64 on every branch and admits
+    // darwin-arm64 under the same gate, so it carries the expression in its
+    // matrix rather than in an `if`.
+    for (const name of [
+      'phase1-conformance',
+      'rust',
+      'unix-supervisor',
+      'windows-supervisor-behavior',
+    ]) {
+      const job = jobs.get(name) ?? '';
+      expect(job).toContain("github.event_name == 'push' && github.ref == 'refs/heads/main'");
+      expect(job).toContain("contains(github.event.pull_request.labels.*.name, 'ci:full')");
+    }
 
     // The classification has to fail towards running everything. A wrong guess
     // that way wastes a few minutes; the other way merges untested code.