fix(chat): drop orphaned pending-id event rows (ghost duplicates)

Mid-flight persists (upload progress, preview updates) could land a DB
row under a message's optimistic pending id; the finalized message then
saved under its REAL id, orphaning the pending-keyed row as a ghost
duplicate that renders on reload. 92 such rows existed in a live
long-running account.

on_sent now deletes the pending-keyed row once the finalized id lands
(session-guarded; the shared delete also retreats a read marker that
pointed at it), and migration 64 sweeps existing orphans. Rows still
flagged pending or failed are live send-state for the retry UI and
stay untouched.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: JSKitty

crates/vector-core/src/db/schema.rs

@@ -749,5 +749,22 @@ pub fn run_migrations(conn: &mut rusqlite::Connection) -> Result<(), String> {
         Ok(())
     })?;
 
+    // =========================================================================
+    // Migration 64: Drop orphaned pending-id event rows
+    // =========================================================================
+    // Mid-flight persists could land a row under a message's optimistic
+    // "pending-…" id; the finalized message then saved under its REAL id,
+    // orphaning the pending-keyed row as a ghost duplicate that renders on
+    // reload. Rows still flagged pending/failed are live send-state (the
+    // retry UI needs them) and stay.
+    run_atomic_migration(conn, 64, "Drop orphaned pending-id event rows", |tx| {
+        tx.execute(
+            "DELETE FROM events WHERE id LIKE 'pending-%' AND pending = 0 AND failed = 0",
+            [],
+        )
+        .map_err(|e| format!("Failed to drop orphaned pending rows: {}", e))?;
+        Ok(())
+    })?;
+
     Ok(())
 }

src-tauri/src/message/sending.rs

@@ -100,6 +100,17 @@ impl SendCallback for TauriSendCallback {
 
     fn on_sent(&self, chat_id: &str, old_id: &str, msg: &Message) {
         UPLOAD_CANCEL_FLAGS.lock().unwrap().remove(old_id);
+        // Mid-flight persists (upload progress, previews) can land a DB row
+        // under the optimistic pending id; the finalized message saves under
+        // its real id, orphaning that row as a ghost duplicate on reload.
+        if old_id.starts_with("pending-") && old_id != msg.id {
+            let pending_id = old_id.to_string();
+            let session = vector_core::state::SessionGuard::capture();
+            tokio::spawn(async move {
+                if !session.is_valid() { return; }
+                let _ = vector_core::db::events::delete_event(&pending_id);
+            });
+        }
         if let Some(handle) = TAURI_APP.get() {
             handle.emit("message_update", serde_json::json!({
                 "old_id": old_id,