diff --git a/.gitea/workflows/ci-required-drift.yml b/.gitea/workflows/ci-required-drift.yml
index 3cf5e5da..1f6965b3 100644
--- a/.gitea/workflows/ci-required-drift.yml
+++ b/.gitea/workflows/ci-required-drift.yml
@@ -57,7 +57,7 @@ permissions:
 # can produce duplicate comments before the title-search dedup wins.
 concurrency:
   group: ci-required-drift
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 jobs:
   drift:
diff --git a/.gitea/workflows/continuous-synth-e2e.yml b/.gitea/workflows/continuous-synth-e2e.yml
index 569a1119..4016df13 100644
--- a/.gitea/workflows/continuous-synth-e2e.yml
+++ b/.gitea/workflows/continuous-synth-e2e.yml
@@ -92,7 +92,7 @@ permissions:
 # stacking up.
 concurrency:
   group: continuous-synth-e2e
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/e2e-api.yml b/.gitea/workflows/e2e-api.yml
index 55fde08c..eb4aafe5 100644
--- a/.gitea/workflows/e2e-api.yml
+++ b/.gitea/workflows/e2e-api.yml
@@ -101,7 +101,7 @@ concurrency:
   # See e2e-staging-canvas.yml's identical concurrency block for the full
   # rationale and the 2026-04-28 incident reference.
   group: e2e-api-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/e2e-chat.yml b/.gitea/workflows/e2e-chat.yml
index 57b7da59..bd4d8bc6 100644
--- a/.gitea/workflows/e2e-chat.yml
+++ b/.gitea/workflows/e2e-chat.yml
@@ -32,7 +32,7 @@ on:
 
 concurrency:
   group: e2e-chat-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/e2e-legacy-advisory.yml b/.gitea/workflows/e2e-legacy-advisory.yml
index aeeb83f0..fc536fa0 100644
--- a/.gitea/workflows/e2e-legacy-advisory.yml
+++ b/.gitea/workflows/e2e-legacy-advisory.yml
@@ -15,7 +15,7 @@ on:
 
 concurrency:
   group: e2e-legacy-advisory
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   contents: read
diff --git a/.gitea/workflows/e2e-peer-visibility.yml b/.gitea/workflows/e2e-peer-visibility.yml
index fd272571..da4d8fd5 100644
--- a/.gitea/workflows/e2e-peer-visibility.yml
+++ b/.gitea/workflows/e2e-peer-visibility.yml
@@ -115,7 +115,7 @@ concurrency:
   # would let a queued staging/main push behind a PR run get cancelled,
   # leaving any gate that reads "completed run at SHA" stuck.
   group: e2e-peer-visibility-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/e2e-staging-canvas.yml b/.gitea/workflows/e2e-staging-canvas.yml
index 696863c2..83b57b21 100644
--- a/.gitea/workflows/e2e-staging-canvas.yml
+++ b/.gitea/workflows/e2e-staging-canvas.yml
@@ -62,7 +62,7 @@ concurrency:
   # wasted CI is acceptable given the alternative is losing staging-tip
   # data that auto-promote-staging needs.
   group: e2e-staging-canvas-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/e2e-staging-sanity.yml b/.gitea/workflows/e2e-staging-sanity.yml
index d1b8f8eb..29519c6e 100644
--- a/.gitea/workflows/e2e-staging-sanity.yml
+++ b/.gitea/workflows/e2e-staging-sanity.yml
@@ -26,7 +26,7 @@ env:
 
 concurrency:
   group: e2e-staging-sanity
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   issues: write
diff --git a/.gitea/workflows/handlers-postgres-integration.yml b/.gitea/workflows/handlers-postgres-integration.yml
index 8ebfa034..c5de4d17 100644
--- a/.gitea/workflows/handlers-postgres-integration.yml
+++ b/.gitea/workflows/handlers-postgres-integration.yml
@@ -69,7 +69,7 @@ on:
     branches: [main, staging]
 concurrency:
   group: handlers-pg-integ-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/harness-replays.yml b/.gitea/workflows/harness-replays.yml
index 76559e2d..05ab9974 100644
--- a/.gitea/workflows/harness-replays.yml
+++ b/.gitea/workflows/harness-replays.yml
@@ -54,7 +54,7 @@ concurrency:
   # cancellation deadlock — see e2e-api.yml's concurrency block for
   # the 2026-04-28 incident that codified this pattern.
   group: harness-replays-${{ github.event.pull_request.head.sha || github.sha }}
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 env:
   GITHUB_SERVER_URL: https://git.moleculesai.app
diff --git a/.gitea/workflows/railway-pin-audit.yml b/.gitea/workflows/railway-pin-audit.yml
index 8508f4a8..18b90f4b 100644
--- a/.gitea/workflows/railway-pin-audit.yml
+++ b/.gitea/workflows/railway-pin-audit.yml
@@ -40,7 +40,7 @@ env:
 
 concurrency:
   group: railway-pin-audit
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   issues: write
diff --git a/.gitea/workflows/sweep-aws-secrets.yml b/.gitea/workflows/sweep-aws-secrets.yml
index dcd00bfb..63f1565c 100644
--- a/.gitea/workflows/sweep-aws-secrets.yml
+++ b/.gitea/workflows/sweep-aws-secrets.yml
@@ -50,7 +50,7 @@ on:
 # Don't let two sweeps race the same AWS account.
 concurrency:
   group: sweep-aws-secrets
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   contents: read
diff --git a/.gitea/workflows/sweep-cf-orphans.yml b/.gitea/workflows/sweep-cf-orphans.yml
index 1400529d..5efb2269 100644
--- a/.gitea/workflows/sweep-cf-orphans.yml
+++ b/.gitea/workflows/sweep-cf-orphans.yml
@@ -58,7 +58,7 @@ on:
 # scheduled run would otherwise issue duplicate DELETE calls.
 concurrency:
   group: sweep-cf-orphans
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   contents: read
diff --git a/.gitea/workflows/sweep-cf-tunnels.yml b/.gitea/workflows/sweep-cf-tunnels.yml
index 085534e5..cfed4e92 100644
--- a/.gitea/workflows/sweep-cf-tunnels.yml
+++ b/.gitea/workflows/sweep-cf-tunnels.yml
@@ -42,7 +42,7 @@ on:
 # Don't let two sweeps race the same account.
 concurrency:
   group: sweep-cf-tunnels
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   contents: read
diff --git a/.gitea/workflows/sweep-stale-e2e-orgs.yml b/.gitea/workflows/sweep-stale-e2e-orgs.yml
index 8ba68fba..f859e189 100644
--- a/.gitea/workflows/sweep-stale-e2e-orgs.yml
+++ b/.gitea/workflows/sweep-stale-e2e-orgs.yml
@@ -51,7 +51,7 @@ on:
 # on a manual trigger; queue rather than parallel-delete.
 concurrency:
   group: sweep-stale-e2e-orgs
-  cancel-in-progress: false
+  cancel-in-progress: true
 
 permissions:
   contents: read