feat(tui): add gum dashboard and read-only workflow

tests/mocks/bin/gum

@@ -2,14 +2,49 @@
 set -Eeuo pipefail
 command_name=${0##*/}
 : "${TEST_MOCK_LOG:?TEST_MOCK_LOG must identify the isolated test log}"
-allow_empty=${MOCK_ALLOW_EMPTY_INVOCATION:-}
-printf '%q' "$command_name" >>"$TEST_MOCK_LOG"; for argument in "$@"; do printf ' %q' "$argument" >>"$TEST_MOCK_LOG"; done; printf '\n' >>"$TEST_MOCK_LOG"
-if [[ -n "$allow_empty" && "$allow_empty" != "$command_name" ]]; then
-  printf 'Unexpected mock invocation: %s does not allow empty calls for %s\n' "$command_name" "$allow_empty" >&2
-  exit 99
-fi
-if [[ $# == 0 && "$allow_empty" == "$command_name" ]]; then
+printf '%q' "$command_name" >>"$TEST_MOCK_LOG"
+for argument in "$@"; do printf ' %q' "$argument" >>"$TEST_MOCK_LOG"; done
+printf '\n' >>"$TEST_MOCK_LOG"
+if (($# == 1)) && [[ $1 == --version ]]; then printf 'gum version 0.14.0\n'; exit 0; fi
+subcommand=${1:-}
+if [[ $subcommand == --help || $subcommand == '' ]]; then exit 0; fi
+if (($# >= 2)) && [[ ${!#} == --help ]]; then
+  [[ ${GUM_FAIL_CAPABILITY:-} == "$subcommand" ]] && exit 98
   exit 0
 fi
-printf 'Unexpected mock invocation: %s received arguments\n' "$command_name" >&2
-exit 99
+case $subcommand in
+  style)
+    [[ $# -gt 1 ]] && [[ ${!#} != *'\n'* ]] || exit 98
+    if [[ -n ${GUM_STYLE_CAPTURE:-} ]]; then printf '%s' "${!#}" >"$GUM_STYLE_CAPTURE"; fi
+    printf '%s\n' "${!#}"
+    exit 0
+    ;;
+  table|pager)
+    if [[ -n ${GUM_PAGER_CAPTURE:-} ]]; then cat >"$GUM_PAGER_CAPTURE"; else cat >/dev/null; fi
+    exit 0
+    ;;
+  spin) exit 0 ;;
+  choose|filter|input|confirm)
+    if [[ -n ${GUM_CHOICES_CAPTURE:-} && ( $subcommand == choose || $subcommand == filter ) ]]; then
+      : >"$GUM_CHOICES_CAPTURE"
+      if [[ $subcommand == filter ]]; then
+        shift 3
+      else
+        shift
+      fi
+      printf '%s\n' "$@" >>"$GUM_CHOICES_CAPTURE"
+    fi
+    script=${GUM_SCRIPT_FILE:-}; answer=''
+    if [[ -n $script && -f $script ]]; then
+      IFS= read -r answer <"$script" || answer=''
+      tail -n +2 -- "$script" >"${script}.next"
+      mv -- "${script}.next" "$script"
+    fi
+    case $subcommand in
+      confirm) [[ $answer == y || $answer == Y ]] || exit 1; exit 0 ;;
+      input) printf '%s\n' "$answer"; exit 0 ;;
+      *) [[ -n $answer ]] && printf '%s\n' "$answer" || exit 1; exit 0 ;;
+    esac
+    ;;
+  *) printf 'Unexpected gum subcommand: %s\n' "$subcommand" >&2; exit 99 ;;
+esac