Add network diagnostics tools and rescue guide documentation

Packages added:
- mtr: combined ping + traceroute
- iperf3: bandwidth testing
- iftop: live bandwidth monitor by connection
- nethogs: bandwidth monitor by process
- ethtool: NIC configuration and diagnostics
- tcpdump: packet capture
- bind: dig/nslookup DNS tools
- nmap: network scanner
- wireshark-cli: tshark packet analysis

Rescue guide section 7 expanded with scenarios for:
- Network path analysis with mtr
- Bandwidth testing with iperf3
- Live monitoring with iftop and nethogs
- Interface diagnostics with ethtool
- Packet capture with tcpdump
- Network scanning with nmap
- Deep packet analysis with tshark

1 files changed, 11 insertions, 0 deletions

diff --git a/build.sh b/build.sh
index f034aec..8073423 100755
--- a/build.sh
+++ b/build.sh
@@ -175,6 +175,17 @@ btrfs-progs
 f2fs-tools
 exfatprogs
 
+# Network diagnostics
+mtr
+iperf3
+iftop
+nethogs
+ethtool
+tcpdump
+bind
+nmap
+wireshark-cli
+
 EOF
 
 # Get kernel version for ISO naming