refactor: simplify ui and log defaults

Remove support for obscure env var overrides in favor of sensible defaults.

lib/core/log.sh

@@ -38,7 +38,7 @@ rotate_log_once() {
     [[ -n "${MOLE_LOG_ROTATED:-}" ]] && return 0
     export MOLE_LOG_ROTATED=1
 
-    local max_size="${MOLE_MAX_LOG_SIZE:-$LOG_MAX_SIZE_DEFAULT}"
+    local max_size="$LOG_MAX_SIZE_DEFAULT"
     if [[ -f "$LOG_FILE" ]] && [[ $(get_file_size "$LOG_FILE") -gt "$max_size" ]]; then
         mv "$LOG_FILE" "${LOG_FILE}.old" 2> /dev/null || true
         ensure_user_file "$LOG_FILE"

lib/core/ui.sh

@@ -321,7 +321,7 @@ stop_inline_spinner() {
 with_spinner() {
     local msg="$1"
     shift || true
-    local timeout="${MOLE_CMD_TIMEOUT:-180}"
+    local timeout=180
     start_inline_spinner "$msg"
     local exit_code=0
     if [[ -n "${MOLE_TIMEOUT_BIN:-}" ]]; then
@@ -333,7 +333,7 @@ with_spinner() {
 
 # Get spinner characters
 mo_spinner_chars() {
-    local chars="${MO_SPINNER_CHARS:-|/-\\}"
+    local chars="|/-\\"
     [[ -z "$chars" ]] && chars="|/-\\"
     printf "%s" "$chars"
 }