fix(service): add service vs interactive detection to start.sh

- Fix hanging rcctl/systemd service starts
- Background mode (&) when no TTY (service context)
- Foreground mode (exec) for interactive usage
- POSIX-compatible detection via [ ! -t 0 ]

Fixes service timeout issues on OpenBSD rcctl and Linux systemd.
Tested on werner - service starts correctly and survives reboots.

Fixes DAW/furt#99

scripts/start.sh

@@ -61,6 +61,16 @@ $LUA_COMMAND -e "require('cjson')" 2>/dev/null || {
 cd "$PROJECT_DIR"
 
 echo -e "${GREEN}Starting Furt...${NC}"
-# Furt liest selbst seine Config aus furt.conf
-exec "$LUA_COMMAND" src/main.lua
+
+# Service vs Interactive Detection
+if [ ! -t 0 ] || [ ! -t 1 ]; then
+    # Service mode - Background
+    "$LUA_COMMAND" src/main.lua &
+else
+    # Interactive mode - Foreground  
+    exec "$LUA_COMMAND" src/main.lua
+fi
+
+# Furt liest selbst seine Config aus furt.conf
+#exec "$LUA_COMMAND" src/main.lua