Add transactional emails (SMTP) and planner features (no-go areas, notes, crash recovery)

Transactional emails:
- Add nodemailer SMTP email module with dev-mode console logging
- Magic link template and welcome template with HTML + plain text
- Wire sendMagicLink into login flow, sendWelcome into registration
- Update privacy page and deploy docs for SMTP configuration

Planner features:
- No-go areas: draw polygons on map (leaflet-geoman), synced via Yjs,
  passed to BRouter as nogos parameter, route recomputes on change
- Session notes: collaborative Y.Text textarea in sidebar tab
- Crash recovery: periodic localStorage save of Yjs state, restore on reconnect
- Rate limit session creation (10/IP/hour) in /new route

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/planner/app/components/NotesPanel.tsx

@@ -0,0 +1,66 @@
+import { useEffect, useRef, useCallback } from "react";
+import type { YjsState } from "~/lib/use-yjs";
+
+interface NotesPanelProps {
+  yjs: YjsState;
+}
+
+export function NotesPanel({ yjs }: NotesPanelProps) {
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+  const isLocalChange = useRef(false);
+
+  // Sync Y.Text → textarea
+  useEffect(() => {
+    const textarea = textareaRef.current;
+    if (!textarea) return;
+
+    // Set initial value
+    textarea.value = yjs.notes.toString();
+
+    const observer = () => {
+      if (isLocalChange.current) return;
+      const pos = textarea.selectionStart;
+      textarea.value = yjs.notes.toString();
+      textarea.selectionStart = pos;
+      textarea.selectionEnd = pos;
+    };
+
+    yjs.notes.observe(observer);
+    return () => yjs.notes.unobserve(observer);
+  }, [yjs.notes]);
+
+  // textarea → Y.Text
+  const handleInput = useCallback(
+    (e: React.FormEvent<HTMLTextAreaElement>) => {
+      const textarea = e.currentTarget;
+      const newValue = textarea.value;
+      const currentValue = yjs.notes.toString();
+
+      if (newValue === currentValue) return;
+
+      isLocalChange.current = true;
+      yjs.doc.transact(() => {
+        yjs.notes.delete(0, yjs.notes.length);
+        yjs.notes.insert(0, newValue);
+      });
+      isLocalChange.current = false;
+    },
+    [yjs.notes, yjs.doc],
+  );
+
+  return (
+    <div className="flex h-full flex-col">
+      <div className="border-b border-gray-200 px-4 py-3">
+        <h2 className="text-sm font-medium text-gray-900">Notes</h2>
+      </div>
+      <div className="flex-1 p-2">
+        <textarea
+          ref={textareaRef}
+          onInput={handleInput}
+          className="h-full w-full resize-none rounded border border-gray-200 p-3 text-sm text-gray-700 placeholder-gray-400 focus:border-blue-300 focus:outline-none"
+          placeholder="Add notes for this session..."
+        />
+      </div>
+    </div>
+  );
+}