Add follow/unfollow (NIP-02) from profile view

- publishContactList (kind 3) in nostr lib — replaces full follow list on each change
- follow() and unfollow() actions in user store with optimistic UI update
- Follow/Unfollow button in ProfileView header (visible when logged in, not own profile)
- Button shows "unfollow" in muted style with danger hover when already following

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/profile/ProfileView.tsx

@@ -99,7 +99,7 @@ function EditProfileForm({ pubkey, onSaved }: { pubkey: string; onSaved: () => v
 
 export function ProfileView() {
   const { selectedPubkey, goBack } = useUIStore();
-  const { pubkey: ownPubkey } = useUserStore();
+  const { pubkey: ownPubkey, loggedIn, follows, follow, unfollow } = useUserStore();
   const pubkey = selectedPubkey!;
   const isOwn = pubkey === ownPubkey;
 
@@ -107,6 +107,22 @@ export function ProfileView() {
   const [notes, setNotes] = useState<NDKEvent[]>([]);
   const [loading, setLoading] = useState(true);
   const [editing, setEditing] = useState(false);
+  const [followPending, setFollowPending] = useState(false);
+
+  const isFollowing = follows.includes(pubkey);
+
+  const handleFollowToggle = async () => {
+    setFollowPending(true);
+    try {
+      if (isFollowing) {
+        await unfollow(pubkey);
+      } else {
+        await follow(pubkey);
+      }
+    } finally {
+      setFollowPending(false);
+    }
+  };
 
   const name = profile?.displayName || profile?.name || shortenPubkey(pubkey);
   const avatar = profile?.picture;
@@ -144,6 +160,19 @@ export function ProfileView() {
             edit profile
           </button>
         )}
+        {!isOwn && loggedIn && (
+          <button
+            onClick={handleFollowToggle}
+            disabled={followPending}
+            className={`text-[11px] px-3 py-1 border transition-colors disabled:opacity-40 disabled:cursor-not-allowed ${
+              isFollowing
+                ? "border-border text-text-muted hover:text-danger hover:border-danger/40"
+                : "border-accent/60 text-accent hover:bg-accent hover:text-white"
+            }`}
+          >
+            {followPending ? "…" : isFollowing ? "unfollow" : "follow"}
+          </button>
+        )}
       </header>
 
       <div className="flex-1 overflow-y-auto">

src/lib/nostr/client.ts

@@ -191,6 +191,17 @@ export async function fetchUserNotes(pubkey: string, limit = 30): Promise<NDKEve
   return Array.from(events).sort((a, b) => (b.created_at ?? 0) - (a.created_at ?? 0));
 }
 
+export async function publishContactList(pubkeys: string[]): Promise<void> {
+  const instance = getNDK();
+  if (!instance.signer) throw new Error("Not logged in");
+
+  const event = new NDKEvent(instance);
+  event.kind = 3;
+  event.content = "";
+  event.tags = pubkeys.map((pk) => ["p", pk]);
+  await event.publish();
+}
+
 export async function fetchProfile(pubkey: string) {
   const instance = getNDK();
   const user = instance.getUser({ pubkey });

src/lib/nostr/index.ts

@@ -1 +1 @@
-export { getNDK, connectToRelays, fetchGlobalFeed, fetchFollowFeed, fetchReplies, publishNote, publishArticle, publishProfile, publishReaction, publishReply, fetchUserNotes, fetchProfile } from "./client";
+export { getNDK, connectToRelays, fetchGlobalFeed, fetchFollowFeed, fetchReplies, publishNote, publishArticle, publishProfile, publishReaction, publishReply, publishContactList, fetchUserNotes, fetchProfile } from "./client";

src/stores/user.ts

@@ -1,6 +1,6 @@
 import { create } from "zustand";
 import { NDKPrivateKeySigner } from "@nostr-dev-kit/ndk";
-import { getNDK } from "../lib/nostr";
+import { getNDK, publishContactList } from "../lib/nostr";
 import { nip19 } from "@nostr-dev-kit/ndk";
 
 interface UserState {
@@ -16,6 +16,8 @@ interface UserState {
   logout: () => void;
   fetchOwnProfile: () => Promise<void>;
   fetchFollows: () => Promise<void>;
+  follow: (pubkey: string) => Promise<void>;
+  unfollow: (pubkey: string) => Promise<void>;
 }
 
 export const useUserStore = create<UserState>((set, get) => ({
@@ -130,4 +132,19 @@ export const useUserStore = create<UserState>((set, get) => ({
       // Non-critical
     }
   },
+
+  follow: async (pubkey: string) => {
+    const { follows } = get();
+    if (follows.includes(pubkey)) return;
+    const updated = [...follows, pubkey];
+    set({ follows: updated });
+    await publishContactList(updated);
+  },
+
+  unfollow: async (pubkey: string) => {
+    const { follows } = get();
+    const updated = follows.filter((pk) => pk !== pubkey);
+    set({ follows: updated });
+    await publishContactList(updated);
+  },
 }));