feat(relay): grow DMs in place, identified by their people

crates/buzz-cli/src/commands/dms.rs

@@ -137,11 +137,13 @@ pub async fn cmd_add_dm_member(
     client: &BuzzClient,
     channel_id: &str,
     pubkey: &str,
+    include_history: bool,
 ) -> Result<(), CliError> {
     let channel_uuid = parse_uuid(channel_id)?;
     validate_hex64(pubkey)?;
 
-    let builder = buzz_sdk::build_dm_add_member(channel_uuid, pubkey).map_err(sdk_err)?;
+    let builder =
+        buzz_sdk::build_dm_add_member(channel_uuid, pubkey, include_history).map_err(sdk_err)?;
     let event = client.sign_event(builder).await?;
 
     let resp = client.submit_event(event).await?;
@@ -154,7 +156,11 @@ pub async fn dispatch(cmd: crate::DmsCmd, client: &BuzzClient) -> Result<(), Cli
     match cmd {
         DmsCmd::List { limit } => cmd_list_dms(client, limit).await,
         DmsCmd::Open { pubkeys } => cmd_open_dm(client, &pubkeys).await,
-        DmsCmd::AddMember { channel, pubkey } => cmd_add_dm_member(client, &channel, &pubkey).await,
+        DmsCmd::AddMember {
+            channel,
+            pubkey,
+            include_history,
+        } => cmd_add_dm_member(client, &channel, &pubkey, include_history).await,
         DmsCmd::Hide { channel } => cmd_hide_dm(client, &channel).await,
     }
 }

crates/buzz-cli/src/lib.rs

@@ -1326,6 +1326,11 @@ pub enum DmsCmd {
         /// User pubkey to add (64-char hex)
         #[arg(long)]
         pubkey: String,
+        /// Add them to this DM with its history, instead of starting a new DM
+        /// of everyone. A person added to a DM of one person and their agents
+        /// always starts a new DM.
+        #[arg(long)]
+        include_history: bool,
     },
     /// Hide a DM conversation from your DM list
     Hide {

crates/buzz-db/src/store/admission_postgres_tests.rs

@@ -491,7 +491,7 @@ async fn dm_writers_require_application_admission() {
     let participants: [&[u8]; 2] = [&[1; 32], &[2; 32]];
     for community in &communities[1..] {
         assert_fenced(
-            super::dm::create_dm(&db.pool, *community, &participants, participants[0])
+            super::dm::create_dm(&db.pool, *community, &participants, participants[0], false)
                 .await
                 .expect_err("DM create must reject"),
         );
@@ -501,9 +501,15 @@ async fn dm_writers_require_application_admission() {
                 .expect_err("DM hide must reject"),
         );
     }
-    super::dm::create_dm(&db.pool, communities[0], &participants, participants[0])
-        .await
-        .expect("active DM create succeeds");
+    super::dm::create_dm(
+        &db.pool,
+        communities[0],
+        &participants,
+        participants[0],
+        false,
+    )
+    .await
+    .expect("active DM create succeeds");
 }
 
 #[tokio::test]

crates/buzz-db/src/store/channel_members.rs

@@ -894,7 +894,10 @@ pub(crate) async fn put_members_with_event(
 /// tag, the TTL reaper's single UPDATE), and none of them takes the
 /// membership lock. So an archive either commits before [`put_members_on`]
 /// reads `archived_at`, or waits until this write commits.
-async fn lock_channel_for_member_put(tx: &mut AdmittedTx, channel_id: Uuid) -> Result<()> {
+pub(crate) async fn lock_channel_for_member_put(
+    tx: &mut AdmittedTx,
+    channel_id: Uuid,
+) -> Result<()> {
     let community_id = tx.community();
     acquire_channel_membership_lock(tx.conn(), community_id, channel_id).await?;
     lock_channel_ttl_shared_in_transaction(tx, channel_id).await?;
@@ -1195,6 +1198,7 @@ pub async fn remove_member(
     if result.rows_affected() == 0 {
         return Err(DbError::MemberNotFound(channel_id));
     }
+    crate::dm::release_dm_identity(tx.conn(), community_id, channel_id).await?;
 
     tx.commit().await?;
     Ok(())