fix(scripts): SIGPIPE-safe first-line selection in 5 scripts

Five scripts used `| head -1 |` (or `| head -n 1 |`) inside pipelines
under `set -euo pipefail`. When the upstream producer emits multiple
lines, `head` closes its stdin after reading line 1 and SIGPIPE (141)
propagates back, terminating the pipeline and — under pipefail —
aborting the script.

Trigger cases:
- Multi-GPU NVIDIA hosts: nvidia-smi emits N lines -> pre-download.sh
  and dream-preflight.sh abort during model selection / GPU probe.
- 2+ downloaded GGUFs: ls -1 *.gguf -> check-offline-models.sh aborts.
- Duplicate keys in .env: grep matches multiple lines -> read_env_value
  and read_searxng_secret silently return empty values (|| true
  suppresses abort but VAR is empty/truncated).

Replace with `| sed -n '1p' |` -- identical on BSD and GNU sed,
consumes full stdin so upstream producers never receive SIGPIPE.

Author: yasinBursali

dream-server/installers/macos/dream-macos.sh

@@ -155,7 +155,7 @@ read_env_value() {
     local env_file="$1"
     local key="$2"
     [[ -f "$env_file" ]] || { echo ""; return 0; }
-    grep -E "^${key}=" "$env_file" 2>/dev/null | head -n 1 | cut -d'=' -f2- | tr -d '\r' || true
+    grep -E "^${key}=" "$env_file" 2>/dev/null | sed -n '1p' | cut -d'=' -f2- | tr -d '\r' || true
 }
 
 upsert_env_value() {

dream-server/installers/macos/lib/env-generator.sh

@@ -36,7 +36,7 @@ read_env_value() {
     local env_path="$1"
     local key="$2"
     [[ -f "$env_path" ]] || { echo ""; return 0; }
-    grep -E "^${key}=" "$env_path" 2>/dev/null | head -n 1 | cut -d'=' -f2- | tr -d '\r' || true
+    grep -E "^${key}=" "$env_path" 2>/dev/null | sed -n '1p' | cut -d'=' -f2- | tr -d '\r' || true
 }
 
 # Read SearXNG secret_key from an existing settings.yml file.
@@ -48,7 +48,7 @@ read_searxng_secret() {
     [[ -f "$settings_path" ]] || { echo ""; return 0; }
     # Expected line format: secret_key: "...."
     grep -E '^[[:space:]]*secret_key:[[:space:]]*"' "$settings_path" 2>/dev/null \
-        | head -n 1 \
+        | sed -n '1p' \
         | sed -E 's/^[[:space:]]*secret_key:[[:space:]]*"([^"]+)".*$/\1/' \
         | tr -d '\r' || true
 }

dream-server/scripts/check-offline-models.sh

@@ -24,7 +24,7 @@ MISSING=()
 
 # Check LLM model (GGUF)
 if ls data/models/*.gguf &>/dev/null; then
-    MODEL_FILE=$(ls -1 data/models/*.gguf | head -1)
+    MODEL_FILE=$(ls -1 data/models/*.gguf | sed -n '1p')
     echo -e "${GREEN}✓${NC} LLM model: $(basename "$MODEL_FILE")"
 else
     echo -e "${RED}✗${NC} LLM model (GGUF) - MISSING"

dream-server/scripts/dream-preflight.sh

@@ -84,7 +84,7 @@ fi
 # Check GPU if available
 echo -n "GPU availability... "
 if docker exec "$LLM_CONTAINER" nvidia-smi >/dev/null 2>&1; then
-    GPU_MEM=$(docker exec "$LLM_CONTAINER" nvidia-smi --query-gpu=memory.free --format=csv,noheader,nounits 2>/dev/null | head -1 | tr -d ' ')
+    GPU_MEM=$(docker exec "$LLM_CONTAINER" nvidia-smi --query-gpu=memory.free --format=csv,noheader,nounits 2>/dev/null | sed -n '1p' | tr -d ' ')
     echo -e "${GREEN}✓ detected (${GPU_MEM}MB free)${NC}"
 else
     echo -e "${YELLOW}⚠ not detected (CPU mode)${NC}"

dream-server/scripts/pre-download.sh

@@ -109,7 +109,7 @@ check_dependencies() {
 
 detect_vram_gb() {
     if command -v nvidia-smi &>/dev/null; then
-        nvidia-smi --query-gpu=memory.total --format=csv,noheader,nounits 2>/dev/null | head -1 | awk '{print int($1/1024)}'
+        nvidia-smi --query-gpu=memory.total --format=csv,noheader,nounits 2>/dev/null | sed -n '1p' | awk '{print int($1/1024)}'
     else
         echo "0"
     fi