Add NIP-17 gift-wrapped DMs, follow-from-menu, fix new conversation crash

DMs now send via NIP-17 (kind 1059 gift-wrap) with self-copy for sent
messages. Receive supports both NIP-17 and legacy NIP-04 for backward
compat. Protocol indicator shown in conversation list and compose footer.

Note card context menu (⋯) now includes follow/unfollow option so users
can follow authors directly from the feed without visiting their profile.

Fix crash (black screen) when starting a new DM conversation — empty
event array caused undefined access on lastEvent.

src/components/dm/DMView.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useRef, useState } from "react";
-import { NDKEvent, nip19 } from "@nostr-dev-kit/ndk";
+import { NDKEvent, NDKKind, nip19 } from "@nostr-dev-kit/ndk";
 import { useUserStore } from "../../stores/user";
 import { useUIStore } from "../../stores/ui";
 import { useNotificationsStore } from "../../stores/notifications";
@@ -68,7 +68,9 @@ function ConvRow({
           <span className="text-text text-[12px] font-medium truncate">{name}</span>
           <span className="text-text-dim text-[10px] shrink-0">{time}</span>
         </div>
-        <div className="text-text-dim text-[11px] truncate">🔒 encrypted</div>
+        <div className="text-text-dim text-[11px] truncate">
+          {lastEvent.kind === NDKKind.PrivateDirectMessage ? "🔒 NIP-17" : "🔒 NIP-04"}
+        </div>
       </div>
     </button>
   );
@@ -139,6 +141,7 @@ function ThreadPanel({
     setMessages([]);
     fetchDMThread(myPubkey, partnerPubkey)
       .then(setMessages)
+      .catch((err) => console.error("Failed to fetch DM thread:", err))
       .finally(() => setLoading(false));
   }, [partnerPubkey, myPubkey]);
 
@@ -222,7 +225,7 @@ function ThreadPanel({
             {sending ? "…" : "send"}
           </button>
         </div>
-        <p className="text-text-dim text-[10px] mt-1">Ctrl+Enter to send · NIP-04 encrypted</p>
+        <p className="text-text-dim text-[10px] mt-1">Ctrl+Enter to send · gift-wrapped (NIP-17)</p>
       </div>
     </div>
   );
@@ -314,6 +317,7 @@ export function DMView() {
         }));
         useNotificationsStore.getState().computeDMUnread(convList);
       })
+      .catch((err) => console.error("Failed to fetch DM conversations:", err))
       .finally(() => setLoading(false));
   }, [pubkey, hasSigner]);
 
@@ -355,18 +359,34 @@ export function DMView() {
               No messages yet.
             </div>
           )}
-          {sortedPartners.map(([partner, events]) => (
-            <ConvRow
-              key={partner}
-              partnerPubkey={partner}
-              lastEvent={events[0]}
-              selected={selectedPubkey === partner}
-              onSelect={() => {
-                setSelectedPubkey(partner);
-                useNotificationsStore.getState().markDMRead(partner);
-              }}
-            />
-          ))}
+          {sortedPartners.map(([partner, events]) =>
+            events[0] ? (
+              <ConvRow
+                key={partner}
+                partnerPubkey={partner}
+                lastEvent={events[0]}
+                selected={selectedPubkey === partner}
+                onSelect={() => {
+                  setSelectedPubkey(partner);
+                  useNotificationsStore.getState().markDMRead(partner);
+                }}
+              />
+            ) : (
+              <button
+                key={partner}
+                onClick={() => setSelectedPubkey(partner)}
+                className={`w-full flex items-center gap-2.5 px-3 py-2.5 text-left transition-colors ${
+                  selectedPubkey === partner ? "bg-accent/10 border-l-2 border-accent" : "hover:bg-bg-hover border-l-2 border-transparent"
+                }`}
+              >
+                <div className="w-8 h-8 rounded-sm bg-bg-raised border border-border flex items-center justify-center text-text-dim text-xs shrink-0">?</div>
+                <div className="flex-1 min-w-0">
+                  <span className="text-text text-[12px] font-medium truncate block">{shortenPubkey(partner)}</span>
+                  <span className="text-text-dim text-[11px]">New conversation</span>
+                </div>
+              </button>
+            )
+          )}
         </div>
 
         <NewConvInput

src/components/feed/NoteCard.tsx

@@ -39,7 +39,7 @@ export function NoteCard({ event, focused }: NoteCardProps) {
   const nip05 = profile?.nip05;
   const time = event.created_at ? timeAgo(event.created_at) : "";
 
-  const { loggedIn, pubkey: ownPubkey } = useUserStore();
+  const { loggedIn, pubkey: ownPubkey, follows, follow, unfollow } = useUserStore();
   const { mutedPubkeys, mute, unmute } = useMuteStore();
   const isMuted = mutedPubkeys.includes(event.pubkey);
   const { bookmarkedIds, addBookmark, removeBookmark } = useBookmarkStore();
@@ -175,6 +175,12 @@ export function NoteCard({ event, focused }: NoteCardProps) {
                   <>
                     <div className="fixed inset-0 z-[9]" onClick={() => setMenuOpen(false)} />
                     <div className="absolute right-0 top-5 bg-bg-raised border border-border shadow-lg z-10 w-32">
+                      <button
+                        onClick={() => { setMenuOpen(false); follows.includes(event.pubkey) ? unfollow(event.pubkey) : follow(event.pubkey); }}
+                        className="w-full text-left px-3 py-2 text-[11px] text-text-muted hover:text-accent hover:bg-bg-hover transition-colors"
+                      >
+                        {follows.includes(event.pubkey) ? `unfollow` : `follow`}
+                      </button>
                       <button
                         onClick={() => { setMenuOpen(false); isMuted ? unmute(event.pubkey) : mute(event.pubkey); }}
                         className="w-full text-left px-3 py-2 text-[11px] text-text-muted hover:text-danger hover:bg-bg-hover transition-colors"