feat(admin): implement management UI and CRUD APIs for all entities

Add full CRUD operations for Pokemon, Habitats, Items, Recipes, and Configs
Switch package manager from npm to pnpm across the project
Remove static seed data in favor of UI-driven data management

frontend/src/styles/main.css

@@ -283,6 +283,76 @@ select {
   font-weight: 800;
 }
 
+.admin-layout {
+  display: grid;
+  grid-template-columns: minmax(320px, 420px) 1fr;
+  gap: 14px;
+  align-items: start;
+}
+
+.form-actions,
+.row-actions,
+.check-row,
+.inline-row,
+.appearance-row {
+  display: flex;
+  gap: 8px;
+}
+
+.form-actions,
+.check-row {
+  flex-wrap: wrap;
+  align-items: center;
+}
+
+.row-actions {
+  flex: 0 0 auto;
+}
+
+.row-actions button,
+.plain-button,
+.inline-row button,
+.appearance-row button {
+  min-height: 34px;
+  padding: 6px 10px;
+  border: 1px solid #c7c0b2;
+  border-radius: 8px;
+  background: #fffdfa;
+  color: #4e5c52;
+  cursor: pointer;
+}
+
+.plain-button {
+  width: fit-content;
+}
+
+.inline-row {
+  align-items: center;
+}
+
+.inline-row select {
+  flex: 1;
+}
+
+.inline-row input {
+  width: 90px;
+}
+
+.appearance-row {
+  display: grid;
+  grid-template-columns: minmax(130px, 1.2fr) minmax(120px, 1fr) repeat(3, minmax(80px, 0.7fr)) auto;
+  align-items: center;
+}
+
+.appearance-row input {
+  min-width: 64px;
+}
+
+button:disabled {
+  cursor: not-allowed;
+  opacity: 0.6;
+}
+
 @media (max-width: 760px) {
   .topbar {
     align-items: start;
@@ -295,7 +365,12 @@ select {
   }
 
   .toolbar,
-  .detail-grid {
+  .detail-grid,
+  .admin-layout {
+    grid-template-columns: 1fr;
+  }
+
+  .appearance-row {
     grid-template-columns: 1fr;
   }
 }