Refactor/core qol adoption (#17655)

* Scripts: close every msg_info block with msg_ok

Past-tense msg_info calls that should have been msg_ok, notices that opened a block before a prompt, and blocks without a closing msg_ok. These already left a stale spinner; with core's block stack they would resume it after every later msg_ok.

* Generate passwords with random_password

openssl rand -base64 | tr -dc | head -c returned fewer characters than asked for, and the unfiltered | cut variants put / and + into passwords that end up in DSNs and sed expressions. Secrets an app decodes as base64 are unchanged. Requires community-scripts/core#61.

* Keep data directories through CLEAN_INSTALL instead of copying them

create_backup copied uploads, storage and similar directories twice per update and needed their size again in free space. CLEAN_INSTALL_KEEP moves them aside instead. Only directories the upstream release does not ship, in scripts that restored right after the fetch. Requires community-scripts/core#61.

* Drop the 300s uv timeout overrides

setup_uv exports UV_HTTP_TIMEOUT=600 now; the scripts' 300 only lowered it. Requires community-scripts/core#61.

tools/addon/jellystat.sh

@@ -137,7 +137,7 @@ function install() {
     echo ""
   else
     # Generate new password
-    DB_PASS=$(openssl rand -base64 18 | tr -dc 'a-zA-Z0-9' | head -c16)
+    DB_PASS=$(random_password 16)
 
     # Check if user exists, create if not
     if sudo -u postgres psql -tAc "SELECT 1 FROM pg_roles WHERE rolname='${DB_USER}'" 2>/dev/null | grep -q 1; then
@@ -187,7 +187,7 @@ function install() {
 
   # Generate JWT Secret
   local JWT_SECRET
-  JWT_SECRET=$(openssl rand -base64 32 | tr -dc 'a-zA-Z0-9' | head -c32)
+  JWT_SECRET=$(random_password 32)
 
   # Force fresh download by removing version cache
   rm -f "$HOME/.jellystat"