fix(ui): use system sleep for inline spinner

lib/core/ui.sh

@@ -342,7 +342,7 @@ start_inline_spinner() {
                 # Output to stderr to avoid interfering with stdout
                 printf "\r${MOLE_SPINNER_PREFIX:-}${BLUE}%s${NC} %s" "$c" "$display_message" >&2 || break
                 i=$((i + 1))
-                sleep 0.05
+                /bin/sleep 0.05
             done
 
             # Clean up stop file before exiting
@@ -366,7 +366,7 @@ stop_inline_spinner() {
         # Wait briefly for cooperative exit
         local wait_count=0
         while kill -0 "$INLINE_SPINNER_PID" 2> /dev/null && [[ $wait_count -lt 5 ]]; do
-            sleep 0.05 2> /dev/null || true
+            /bin/sleep 0.05 2> /dev/null || true
             wait_count=$((wait_count + 1))
         done
 

tests/core_common.bats

@@ -204,10 +204,30 @@ sleep 0.1
 stop_inline_spinner
 echo "done"
 EOF
-)
+    )
     [[ "$result" == *"done"* ]]
 }
 
+@test "start_inline_spinner ignores PATH-provided sleep in TTY mode" {
+    local fake_bin="$HOME/fake-bin"
+    local marker="$HOME/fake-sleep.marker"
+
+    mkdir -p "$fake_bin"
+    cat > "$fake_bin/sleep" <<EOF
+#!/bin/bash
+echo "fake" >> "$marker"
+exec /bin/sleep "\$@"
+EOF
+    chmod +x "$fake_bin/sleep"
+
+    PATH="$fake_bin:$PATH" PROJECT_ROOT="$PROJECT_ROOT" HOME="$HOME" \
+        /usr/bin/script -q /dev/null /bin/bash --noprofile --norc -c \
+        'source "$PROJECT_ROOT/lib/core/common.sh"; start_inline_spinner "Testing..."; /bin/sleep 0.15; stop_inline_spinner' \
+        > /dev/null 2>&1
+
+    [ ! -f "$marker" ]
+}
+
 @test "read_key maps j/k/h/l to navigation" {
     run bash -c "export MOLE_BASE_LOADED=1; source '$PROJECT_ROOT/lib/core/ui.sh'; echo -n 'j' | read_key"
     [ "$output" = "DOWN" ]