Handle non-TTY output; simplify verbosity check

Detect non-TTY stderr in msg_info() and print a static progress indicator instead of launching the background spinner (which is unreliable when output is piped). Remove the non-TTY check from is_verbose_mode() and add comments clarifying that non-TTY behavior is handled in msg_info(). Apply the same verbosity simplification to vm-core.func. This keeps spinner visuals working when passed through pipes while avoiding backgrounding issues.

misc/vm-core.func

@@ -352,11 +352,11 @@ clear_line() {
 #
 # - Determines if script should run in verbose mode
 # - Checks VERBOSE and var_verbose variables
-# - Also returns true if not running in TTY (pipe/redirect scenario)
+# - Note: Non-TTY (pipe) scenarios are handled separately in msg_info()
 # ------------------------------------------------------------------------------
 is_verbose_mode() {
   local verbose="${VERBOSE:-${var_verbose:-no}}"
-  [[ "$verbose" != "no" || ! -t 2 ]]
+  [[ "$verbose" != "no" ]]
 }
 
 ### dev spinner ###