feat: stop subcommand, and disables empty lines from counting as an alarm element

test/nag.bats

@@ -100,6 +100,52 @@ load test_helper
   [[ "${output}" =~ "[1] Tomorrow, 3pm — take a break" ]]
 }
 
+@test "list shows empty message after stopping all alarms" {
+  run_nag at "tomorrow 3pm" "test alarm"
+  run_nag stop 1
+  [ "${status}" -eq 0 ]
+  run_nag
+  [[ "${output}" =~ "Nothing to nag about" ]]
+}
+
+@test "help stop shows stop usage" {
+  run_nag help stop
+  [ "${status}" -eq 0 ]
+  [[ "${output}" =~ "Usage:" ]]
+  [[ "${output}" =~ "stop <id>" ]]
+}
+
+@test "stop removes an alarm by ID" {
+  run_nag at "tomorrow 3pm" "take a break"
+  run_nag stop 1
+  [ "${status}" -eq 0 ]
+  [[ "${output}" =~ "Stopped alarm 1" ]]
+  run_nag
+  [[ "${output}" =~ "Nothing to nag about" ]]
+}
+
+@test "stop removes only the targeted alarm" {
+  run_nag at "tomorrow 3pm" "first"
+  run_nag at "tomorrow 4pm" "second"
+  run_nag at "tomorrow 5pm" "third"
+  run_nag stop 2
+  [ "${status}" -eq 0 ]
+  run_nag
+  [[ "${output}" =~ "first" ]]
+  [[ ! "${output}" =~ "second" ]]
+  [[ "${output}" =~ "third" ]]
+}
+
+@test "stop with nonexistent ID fails" {
+  run_nag stop 99
+  [ "${status}" -eq 1 ]
+}
+
+@test "stop without ID fails" {
+  run_nag stop
+  [ "${status}" -eq 1 ]
+}
+
 @test "list sorts alarms by time" {
   run_nag at "tomorrow 3pm" "take a break"
   run_nag at "tomorrow 9am" "standup"