ux(ui): readable persona form instead of raw JSON + step-by-step guides for non-IT users

- GroupEdit: replace raw JSON persona dump with a labeled, sectioned PersonaForm
  (ข้อมูลพื้นฐาน / ข้อมูลลูกค้า / การขาย / ช่องทาง) shown in a modal; admin edits by field.
- New reusable components/PersonaForm.vue.
- GroupBuilder + Personas: add friendly step-by-step guidance cards ('วิธีสร้าง',
  'วิธีฝึก') so admins/trainees know what to do at each step.
- Rebuild dist.

frontend/dist/assets/Personas-Be_DU4st.css

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+.grid[data-v-0fa25205]{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:14px}.pcard[data-v-0fa25205]{display:flex;flex-direction:column;min-height:190px}.diff[data-v-0fa25205]{margin:8px 0}.star[data-v-0fa25205]{color:#d8dbe3}.star.on[data-v-0fa25205]{color:#f59e0b}.badge.won[data-v-0fa25205]{background:#dcfce7;color:#166534}.badge.lost[data-v-0fa25205]{background:#fee2e2;color:#991b1b}.badge.not_tried[data-v-0fa25205]{background:#eef2ff;color:#4338ca}.guide[data-v-0fa25205]{background:#eef2ff;border-color:#c7d2fe;margin:12px 0 16px}