diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ed934e0..7e6636b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -35,11 +35,11 @@ jobs:
       - uses: actions/checkout@v4
       - name: Check for non-English strings
         run: |
-          GERMAN=$(grep -rlE 'ä|ö|ü|ß' --include='*.sh' . || true)
+          GERMAN=$(grep -rlP '\xc3[\xa4\xb6\xbc\x9f]' --include='*.sh' --exclude-dir=tests . || true)
           if [[ -n "$GERMAN" ]]; then
             echo "Files with German characters:"
             echo "$GERMAN"
-            grep -rnE 'ä|ö|ü|ß' --include='*.sh' .
+            grep -rnP '\xc3[\xa4\xb6\xbc\x9f]' --include='*.sh' --exclude-dir=tests .
             exit 1
           fi
           echo "All clear — no German strings found."
diff --git a/config.sh b/config.sh
index 09f8e2b..4f95095 100755
--- a/config.sh
+++ b/config.sh
@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
-# Night Shift Configuration
+# Night Shift Configuration. Sourced by coordinator.sh, worker.sh, etc.
+# shellcheck disable=SC2034
 # Edit this file to match your environment
 
 # ─── Repositories to scan ───
diff --git a/coordinator.sh b/coordinator.sh
index 7d2fa51..590224d 100755
--- a/coordinator.sh
+++ b/coordinator.sh
@@ -35,9 +35,12 @@ main() {
   log "Ollama: $(curl -s -o /dev/null -w '%{http_code}' http://localhost:11434/api/tags 2>/dev/null || echo 'OFFLINE')"
   log "--- Repo Status ---"
   for rp in "${REPOS[@]}"; do
-    local rn=$(basename "$rp")
-    local rchanges=$(git -C "$rp" status --porcelain 2>/dev/null | wc -l)
-    local rbranch=$(git -C "$rp" branch --show-current 2>/dev/null)
+    local rn
+    rn=$(basename "$rp")
+    local rchanges
+    rchanges=$(git -C "$rp" status --porcelain 2>/dev/null | wc -l)
+    local rbranch
+    rbranch=$(git -C "$rp" branch --show-current 2>/dev/null)
     log "  $rn: Branch=$rbranch, Changes=$rchanges"
   done
   log "---"
diff --git a/tests/test-nightshift.sh b/tests/test-nightshift.sh
index 7a5acad..90d4afe 100755
--- a/tests/test-nightshift.sh
+++ b/tests/test-nightshift.sh
@@ -290,7 +290,7 @@ if command -v shellcheck &>/dev/null; then
   for script in config.sh coordinator.sh worker.sh summary.sh summary-morning.sh lesson-generator.sh install.sh; do
     TESTS_RUN=$((TESTS_RUN + 1))
     sc_output=$(shellcheck -S warning "$PROJECT_DIR/$script" 2>&1 || true)
-    sc_errors=$(echo "$sc_output" | grep -c "^In " || echo "0")
+    sc_errors=$(echo "$sc_output" | grep -c "^In " || true)
     if [[ "$sc_errors" -eq 0 ]]; then
       TESTS_PASSED=$((TESTS_PASSED + 1))
       echo -e "  ${GREEN}PASS${NC} shellcheck: $script"
@@ -313,7 +313,7 @@ echo "=== Language Check (English only) ==="
 german_found=false
 for script in config.sh coordinator.sh worker.sh summary.sh summary-morning.sh lesson-generator.sh install.sh; do
   TESTS_RUN=$((TESTS_RUN + 1))
-  german_lines=$(grep -cE 'ä|ö|ü|ß' "$PROJECT_DIR/$script" 2>/dev/null | tr -d '[:space:]' || echo "0")
+  german_lines=$(grep -cP '\xc3[\xa4\xb6\xbc\x9f]' "$PROJECT_DIR/$script" 2>/dev/null | tr -d '[:space:]' || echo "0")
   german_lines="${german_lines:-0}"
   if [[ "$german_lines" -eq 0 ]]; then
     TESTS_PASSED=$((TESTS_PASSED + 1))
diff --git a/worker.sh b/worker.sh
index 848e7a8..f326128 100755
--- a/worker.sh
+++ b/worker.sh
@@ -18,7 +18,7 @@ main() {
     exit 1
   fi
 
-  IFS='|' read -r repo category title description risk_level llm_tier run_id <<< "$task_data"
+  IFS='|' read -r repo category title description _risk_level llm_tier _run_id <<< "$task_data"
 
   # Resolve repo path — supports both basename and absolute path in REPOS
   local repo_path=""
@@ -32,7 +32,8 @@ main() {
     repo_path="$repo"
   fi
 
-  local branch_name="nightshift/${category}-$(date +%Y%m%d)-$(echo "$title" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | head -c 40)"
+  local branch_name
+  branch_name="nightshift/${category}-$(date +%Y%m%d)-$(echo "$title" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | head -c 40)"
 
   log "Worker started: [$category] $title (Repo: $repo)"
   local safe_branch
@@ -73,7 +74,8 @@ main() {
   if ! git rev-parse --verify "$base_branch" &>/dev/null; then
     base_branch="main"
   fi
-  local backup_tag="nightshift-backup/$(date +%Y%m%d-%H%M%S)-${repo}"
+  local backup_tag
+  backup_tag="nightshift-backup/$(date +%Y%m%d-%H%M%S)-${repo}"
   git tag "$backup_tag" "$base_branch" 2>/dev/null || true
 
   # Create branch