feat: implement merge readiness plan to close gaps between v2 and v1

- Task 1: Fix feed response hydration by adding `to_thought_response` helper and updating feed handlers to return full `ThoughtResponse`.
- Task 2: Wire follower/following REST routes for user feeds.
- Task 3: Add user listing and count endpoints, including `GET /users` and `GET /users/count`.
- Task 4: Implement popular tags feature with `GET /tags/popular`.
- Task 5: Enhance configuration with HOST, CORS_ORIGINS, and optional rate limiting using tower-governor.

crates/adapters/postgres-search/src/lib.rs

@@ -1,6 +1,6 @@
 use async_trait::async_trait;
 use chrono::{DateTime, Utc};
-use sqlx::PgPool;
+use domain::models::thought::Visibility;
 use domain::{
     errors::DomainError,
     models::{
@@ -11,10 +11,16 @@ use domain::{
     ports::SearchPort,
     value_objects::{Content, Email, PasswordHash, ThoughtId, UserId, Username},
 };
-use domain::models::thought::Visibility;
+use sqlx::PgPool;
 
-pub struct PgSearchRepository { pool: PgPool }
-impl PgSearchRepository { pub fn new(pool: PgPool) -> Self { Self { pool } } }
+pub struct PgSearchRepository {
+    pool: PgPool,
+}
+impl PgSearchRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
 
 #[derive(sqlx::FromRow)]
 struct FeedRow {
@@ -87,13 +93,28 @@ fn row_to_entry(r: FeedRow) -> FeedEntry {
         username: Username::from_trusted(r.username),
         email: Email::from_trusted(r.email),
         password_hash: PasswordHash(r.password_hash),
-        display_name: r.display_name, bio: r.bio,
-        avatar_url: r.avatar_url, header_url: r.header_url, custom_css: r.custom_css,
-        local: r.author_local, ap_id: r.u_ap_id, inbox_url: r.inbox_url,
-        public_key: r.public_key, private_key: r.private_key,
-        created_at: r.author_created_at, updated_at: r.author_updated_at,
+        display_name: r.display_name,
+        bio: r.bio,
+        avatar_url: r.avatar_url,
+        header_url: r.header_url,
+        custom_css: r.custom_css,
+        local: r.author_local,
+        ap_id: r.u_ap_id,
+        inbox_url: r.inbox_url,
+        public_key: r.public_key,
+        private_key: r.private_key,
+        created_at: r.author_created_at,
+        updated_at: r.author_updated_at,
     };
-    FeedEntry { thought, author, like_count: r.like_count, boost_count: r.boost_count, reply_count: r.reply_count, liked_by_viewer: false, boosted_by_viewer: false }
+    FeedEntry {
+        thought,
+        author,
+        like_count: r.like_count,
+        boost_count: r.boost_count,
+        reply_count: r.reply_count,
+        liked_by_viewer: false,
+        boosted_by_viewer: false,
+    }
 }
 
 #[derive(sqlx::FromRow)]
@@ -123,11 +144,18 @@ impl From<UserRow> for User {
             username: Username::from_trusted(r.username),
             email: Email::from_trusted(r.email),
             password_hash: PasswordHash(r.password_hash),
-            display_name: r.display_name, bio: r.bio,
-            avatar_url: r.avatar_url, header_url: r.header_url, custom_css: r.custom_css,
-            local: r.local, ap_id: r.ap_id, inbox_url: r.inbox_url,
-            public_key: r.public_key, private_key: r.private_key,
-            created_at: r.created_at, updated_at: r.updated_at,
+            display_name: r.display_name,
+            bio: r.bio,
+            avatar_url: r.avatar_url,
+            header_url: r.header_url,
+            custom_css: r.custom_css,
+            local: r.local,
+            ap_id: r.ap_id,
+            inbox_url: r.inbox_url,
+            public_key: r.public_key,
+            private_key: r.private_key,
+            created_at: r.created_at,
+            updated_at: r.updated_at,
         }
     }
 }
@@ -146,7 +174,7 @@ impl SearchPort for PgSearchRepository {
     ) -> Result<Paginated<FeedEntry>, DomainError> {
         let total: i64 = sqlx::query_scalar(
             "SELECT COUNT(*) FROM thoughts t
-             WHERE t.content % $1 AND t.visibility='public'"
+             WHERE t.content % $1 AND t.visibility='public'",
         )
         .bind(query)
         .fetch_one(&self.pool)
@@ -182,7 +210,7 @@ impl SearchPort for PgSearchRepository {
     ) -> Result<Paginated<User>, DomainError> {
         let total: i64 = sqlx::query_scalar(
             "SELECT COUNT(*) FROM users u
-             WHERE u.local=true AND (u.username % $1 OR u.display_name % $1)"
+             WHERE u.local=true AND (u.username % $1 OR u.display_name % $1)",
         )
         .bind(query)
         .fetch_one(&self.pool)
@@ -216,7 +244,10 @@ impl SearchPort for PgSearchRepository {
 mod tests {
     use super::*;
     use domain::{
-        models::{thought::{Thought, Visibility}, user::User},
+        models::{
+            thought::{Thought, Visibility},
+            user::User,
+        },
         ports::{SearchPort, ThoughtRepository, UserRepository},
         value_objects::*,
     };
@@ -233,9 +264,13 @@ mod tests {
         );
         urepo.save(&u).await.unwrap();
         let t = Thought::new_local(
-            ThoughtId::new(), u.id.clone(),
+            ThoughtId::new(),
+            u.id.clone(),
             Content::new_local(content).unwrap(),
-            None, Visibility::Public, None, false,
+            None,
+            Visibility::Public,
+            None,
+            false,
         );
         trepo.save(&t).await.unwrap();
         (u, t)
@@ -246,7 +281,17 @@ mod tests {
         seed_thought(&pool, "alice", "hello world").await;
         seed_thought(&pool, "bob", "goodbye universe").await;
         let repo = PgSearchRepository::new(pool);
-        let result = repo.search_thoughts("hello world", &PageParams { page: 1, per_page: 20 }, None).await.unwrap();
+        let result = repo
+            .search_thoughts(
+                "hello world",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                None,
+            )
+            .await
+            .unwrap();
         assert_eq!(result.total, 1);
         assert_eq!(result.items[0].thought.content.as_str(), "hello world");
     }
@@ -255,19 +300,46 @@ mod tests {
     async fn search_users_finds_by_username(pool: sqlx::PgPool) {
         use postgres::user::PgUserRepository;
         let urepo = PgUserRepository::new(pool.clone());
-        let alice = User::new_local(UserId::new(), Username::new("alice_search").unwrap(), Email::new("alice@ex.com").unwrap(), PasswordHash("h".into()));
+        let alice = User::new_local(
+            UserId::new(),
+            Username::new("alice_search").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        );
         urepo.save(&alice).await.unwrap();
         let repo = PgSearchRepository::new(pool);
-        let result = repo.search_users("alice", &PageParams { page: 1, per_page: 20 }).await.unwrap();
+        let result = repo
+            .search_users(
+                "alice",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+            )
+            .await
+            .unwrap();
         assert!(!result.items.is_empty());
-        assert!(result.items.iter().any(|u| u.username.as_str() == "alice_search"));
+        assert!(result
+            .items
+            .iter()
+            .any(|u| u.username.as_str() == "alice_search"));
     }
 
     #[sqlx::test(migrations = "../postgres/migrations")]
     async fn search_thoughts_returns_empty_for_no_match(pool: sqlx::PgPool) {
         seed_thought(&pool, "alice", "hello world").await;
         let repo = PgSearchRepository::new(pool);
-        let result = repo.search_thoughts("zzzzzzzzz", &PageParams { page: 1, per_page: 20 }, None).await.unwrap();
+        let result = repo
+            .search_thoughts(
+                "zzzzzzzzz",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                None,
+            )
+            .await
+            .unwrap();
         assert_eq!(result.total, 0);
     }
 }