add journaling feature: categories, tags, attachments, calendar, and multi-select emotions

Adds an 8th development stage that lets users keep a free-form journal alongside
habit tracking, reusing the existing Google OAuth/DB/PWA infrastructure instead
of a separate project. Users organize entries into custom categories, filter by
a month calendar with day-detail drill-down, attach photos/videos (served via an
authenticated route, never /static), tag entries, and pick multiple emotions per
entry from a curated 9-option set. Includes a global journal prompt bank for
lightweight guided journaling.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/static/js/journal-category-reorder.js

@@ -0,0 +1,27 @@
+(function () {
+  function initSortable() {
+    var list = document.getElementById("journal-category-list");
+    if (!list || typeof Sortable === "undefined") return;
+
+    Sortable.create(list, {
+      handle: ".drag-handle",
+      animation: 150,
+      forceFallback: true, // iOS Safari는 네이티브 HTML5 D&D 터치 지원이 불안정해서 자체 포인터 시뮬레이션을 강제한다
+      fallbackTolerance: 3,
+      onEnd: function () {
+        var ids = Array.from(list.children)
+          .map(function (el) { return el.getAttribute("data-category-id"); })
+          .filter(Boolean)
+          .map(Number);
+
+        fetch("/api/journal/categories/reorder", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify({ category_ids: ids }),
+        });
+      },
+    });
+  }
+
+  document.addEventListener("DOMContentLoaded", initSortable);
+})();