fix(installer): SIGPIPE crash in generate_password with pipefail

`tr | head -c 32` causes tr to receive SIGPIPE when head exits early.
With `set -eo pipefail`, exit code 141 kills the script right after
"Configuration validated" before any passwords are generated.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

installer/install.sh

@@ -147,7 +147,7 @@ prompt_yesno() {
 }
 
 generate_password() {
-  tr -dc 'A-Za-z0-9' < /dev/urandom | head -c 32
+  tr -dc 'A-Za-z0-9' < /dev/urandom | head -c 32 || :
 }
 
 # --- Argument parsing ---