diff --git a/.github/workflows/integ.yml b/.github/workflows/integ.yml
index 0586d9a2..692b1010 100644
--- a/.github/workflows/integ.yml
+++ b/.github/workflows/integ.yml
@@ -29,8 +29,10 @@ on:
     types: [completed]
   workflow_dispatch: {}
 
-# Only one integ run at a time against the shared account — overlapping deploys
-# would collide on the single hardcoded `backgroundagent-integ` stack name.
+# Only one integ run at a time against the shared account. Stack names are now
+# run-unique (`int-<sha>`, see the integ job) so this is no longer a correctness
+# requirement — it bounds shared-account cost/parallelism rather than preventing
+# a name collision.
 concurrency:
   group: cdk-integ
   cancel-in-progress: false
@@ -217,30 +219,36 @@ jobs:
       - name: Install dependencies
         run: yarn install --immutable
 
-      - name: Run integ tests (deploy → assert → destroy)
-        run: mise //cdk:integ
-
-      # Safety net: integ-runner forces teardown on success and failure, but if
-      # the run is cancelled or crashes mid-deploy the stack can be stranded in
-      # the shared account. Delete it directly via CloudFormation so we never
-      # leak billable resources.
+      # Teardown: integ-runner forces `cdk destroy` on success and failure (via
+      # the CDK bootstrap roles, which hold the CloudFormation permissions). No
+      # raw-CLI safety net here: the GitHub OIDC role has no
+      # cloudformation:DeleteStack/DescribeStacks, so such a step can only fail
+      # (#566). If a cancelled/crashed run strands the stack, reclaim is the
+      # stranded-stack cleanup owned by #400/#72 — and the run-unique name below
+      # means a stranded stack never blocks a later run.
       #
-      # NOTE: `cdk destroy backgroundagent-integ` would NOT work here — it
-      # synthesizes the main app (src/main.ts), which does not contain the integ
-      # stack, so it exits 0 having deleted nothing. Target the stack by its
-      # literal CloudFormation name instead. delete-stack is idempotent (no-op if
-      # already gone), so `|| true` only guards transient API errors.
-      - name: Ensure stack torn down
-        if: always()
+      # INTEG_STACK_NAME maps the stack to the commit under test plus the run
+      # number (`int-<sha>-<run>`), replacing the single fixed
+      # `backgroundagent-integ` name. The run number makes same-commit re-runs
+      # distinct; the `int-` prefix marks it ephemeral for #72's sweep. HEAD_SHA
+      # is the resolved PR head (or dispatched ref) and RUN_NUMBER is a positive
+      # integer, so both are already lowercase-alphanumeric — no sanitizing
+      # needed to stay CloudFormation-valid.
+      - name: Run integ tests (deploy → assert → destroy)
         env:
-          AWS_REGION: ${{ vars.AWS_REGION || 'us-east-1' }}
-          AWS_DEFAULT_REGION: ${{ vars.AWS_REGION || 'us-east-1' }}
+          HEAD_SHA: ${{ needs.resolve.outputs.head_sha }}
+          RUN_NUMBER: ${{ github.run_number }}
         run: |
           set -euo pipefail
-          aws cloudformation delete-stack --stack-name backgroundagent-integ || true
-          # No `|| true` on the wait: a DELETE_FAILED must surface loudly so we
-          # never silently leak billable resources in the shared account.
-          aws cloudformation wait stack-delete-complete --stack-name backgroundagent-integ
+          export INTEG_STACK_NAME="int-${HEAD_SHA:0:12}-${RUN_NUMBER}"
+          echo "Integ stack name: $INTEG_STACK_NAME"
+          mise //cdk:integ -- --all --require-approval never \
+            -c stackName="integ-${{ github.run_id }}-${{ github.run_attempt }}" \
+            -c github:sha="$(git rev-parse HEAD)" \
+            -c github:ref="$(git branch --show-current || echo "detached")" \
+            -c github:actor="${{ github.triggering_actor }}" \
+            -c github:repository="$(gh repo view --json nameWithOwner --jq .nameWithOwner)" \
+            -c github:clean="$([ -z "$(git status --porcelain)" ] && echo true || echo false)"
 
   # Post the final integ-smoke status back to the PR head so the check flips from
   # pending to success/failure. Skipped for workflow_dispatch (no PR to gate).
diff --git a/cdk/test/integ/integ.task-api-smoke.ts b/cdk/test/integ/integ.task-api-smoke.ts
index 5775de59..c5e78bc3 100644
--- a/cdk/test/integ/integ.task-api-smoke.ts
+++ b/cdk/test/integ/integ.task-api-smoke.ts
@@ -89,8 +89,15 @@ class TaskApiSmokeStack extends Stack {
   }
 }
 
+// Stack name is run-unique in CI (`int-<short-sha>-<run-number>`, set by
+// integ.yml) so a stranded stack from a cancelled/crashed run never collides
+// with — or blocks — a later run under one fixed name. Falls back to a stable
+// local name so the `mise //cdk:integ` dev path is unchanged. The `int-` prefix
+// keeps it letter-led and the rest is lowercase-alphanumeric + hyphens, so the
+// name is CloudFormation-valid.
 const app = new App();
-const stack = new TaskApiSmokeStack(app, 'backgroundagent-integ');
+const stackName = process.env.INTEG_STACK_NAME || 'backgroundagent-integ-local';
+const stack = new TaskApiSmokeStack(app, stackName);
 
 const integ = new IntegTest(app, 'TaskApiSmoke', {
   testCases: [stack],