fix: Correct Back Navigation & Use Existing Dialog Pattern! 🔧

## Issue #1: Back Button Navigation Fixed

**Problem:** Back button navigated too far to Notifications.tsx
**Root Cause:** Wrong route - should go to /staff or /customer page with templates tab

**Solution:**
- Detect if staff or customer event
- Navigate to `/settings/notifications/{staff|customer}?tab=templates`
- Staff.tsx and Customer.tsx read tab query param
- Auto-open templates tab on return

**Files:**
- `routes/Settings/Notifications/EditTemplate.tsx`
- `routes/Settings/Notifications/Staff.tsx`
- `routes/Settings/Notifications/Customer.tsx`

## Issue #2: Dialog Pattern - Use Existing, Dont Reinvent!

**Problem:** Created new DialogBody component, over-engineered
**Root Cause:** Didnt check existing dialog usage in project

**Solution:**
- Reverted dialog.tsx to original
- Use existing pattern from Shipping.tsx:
  ```tsx
  <DialogContent className="max-h-[90vh] overflow-y-auto">
  ```
- Simple, proven, works!

**Files:**
- `components/ui/dialog.tsx` - Reverted to original
- `components/ui/rich-text-editor.tsx` - Use existing pattern

**Lesson Learned:**
Always scan project for existing patterns before creating new ones!

Both issues fixed! ✅

admin-spa/package-lock.json

@@ -9,6 +9,7 @@
             "version": "0.0.1",
             "dependencies": {
                 "@codemirror/lang-html": "^6.4.11",
+                "@codemirror/lang-markdown": "^6.5.0",
                 "@codemirror/theme-one-dark": "^6.1.3",
                 "@dnd-kit/core": "^6.3.1",
                 "@dnd-kit/sortable": "^10.0.0",
@@ -444,6 +445,21 @@
                 "@lezer/javascript": "^1.0.0"
             }
         },
+        "node_modules/@codemirror/lang-markdown": {
+            "version": "6.5.0",
+            "resolved": "https://registry.npmjs.org/@codemirror/lang-markdown/-/lang-markdown-6.5.0.tgz",
+            "integrity": "sha512-0K40bZ35jpHya6FriukbgaleaqzBLZfOh7HuzqbMxBXkbYMJDxfF39c23xOgxFezR+3G+tR2/Mup+Xk865OMvw==",
+            "license": "MIT",
+            "dependencies": {
+                "@codemirror/autocomplete": "^6.7.1",
+                "@codemirror/lang-html": "^6.0.0",
+                "@codemirror/language": "^6.3.0",
+                "@codemirror/state": "^6.0.0",
+                "@codemirror/view": "^6.0.0",
+                "@lezer/common": "^1.2.1",
+                "@lezer/markdown": "^1.0.0"
+            }
+        },
         "node_modules/@codemirror/language": {
             "version": "6.11.3",
             "resolved": "https://registry.npmjs.org/@codemirror/language/-/language-6.11.3.tgz",
@@ -1361,6 +1377,16 @@
                 "@lezer/common": "^1.0.0"
             }
         },
+        "node_modules/@lezer/markdown": {
+            "version": "1.6.0",
+            "resolved": "https://registry.npmjs.org/@lezer/markdown/-/markdown-1.6.0.tgz",
+            "integrity": "sha512-AXb98u3M6BEzTnreBnGtQaF7xFTiMA92Dsy5tqEjpacbjRxDSFdN4bKJo9uvU4cEEOS7D2B9MT7kvDgOEIzJSw==",
+            "license": "MIT",
+            "dependencies": {
+                "@lezer/common": "^1.0.0",
+                "@lezer/highlight": "^1.0.0"
+            }
+        },
         "node_modules/@marijn/find-cluster-break": {
             "version": "1.0.2",
             "resolved": "https://registry.npmjs.org/@marijn/find-cluster-break/-/find-cluster-break-1.0.2.tgz",