diff --git a/.github/workflows/docs-drift.yml b/.github/workflows/docs-drift.yml
index 15fcead2..c76bff9a 100644
--- a/.github/workflows/docs-drift.yml
+++ b/.github/workflows/docs-drift.yml
@@ -8,6 +8,10 @@ on:
       - 'docs/api.md'
       - '.github/workflows/docs-drift.yml'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 permissions:
   contents: read
   pull-requests: read
diff --git a/.github/workflows/mobile-shell-typecheck.yml b/.github/workflows/mobile-shell-typecheck.yml
index faa0f635..45e91f22 100644
--- a/.github/workflows/mobile-shell-typecheck.yml
+++ b/.github/workflows/mobile-shell-typecheck.yml
@@ -11,6 +11,10 @@ on:
       - "mobile/tauri/**"
       - ".github/workflows/mobile-shell-typecheck.yml"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   cargo-check:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/qc.yml b/.github/workflows/qc.yml
index f7f1665f..c1af67d5 100644
--- a/.github/workflows/qc.yml
+++ b/.github/workflows/qc.yml
@@ -3,10 +3,24 @@ name: QC
 on:
   pull_request:
     branches: [main]
+    paths-ignore:
+      - '**.md'
+      - 'docs/**'
+      - '.gitignore'
+      - 'LICENSE'
   push:
     branches: [main]
+    paths-ignore:
+      - '**.md'
+      - 'docs/**'
+      - '.gitignore'
+      - 'LICENSE'
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   pr-gate:
     name: PR gate (typecheck + baseline + migration)
diff --git a/.github/workflows/release-supervisor.yml b/.github/workflows/release-supervisor.yml
index bb288531..8e3285e8 100644
--- a/.github/workflows/release-supervisor.yml
+++ b/.github/workflows/release-supervisor.yml
@@ -10,6 +10,10 @@ on:
     tags:
       - 'supervisor-v*.*.*'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
 permissions:
   contents: write   # tauri-action creates a GitHub Release