Implement EuphVault

cove-tui/src/vault/migrate.rs

@@ -57,6 +57,20 @@ fn m1(tx: &mut Transaction) -> rusqlite::Result<()> {
             FOREIGN KEY (room, start) REFERENCES euph_msgs (room, start),
             FOREIGN KEY (room, end) REFERENCES euph_msgs (room, end)
         ) STRICT;
+
+        CREATE VIEW euph_trees (room, id) AS
+        SELECT room, id
+        FROM euph_msgs
+        WHERE parent IS NULL
+        UNION
+        (
+            SELECT room, parent
+            FROM euph_msgs
+            WHERE parent IS NOT NULL
+            EXCEPT
+            SELECT room, id
+            FROM euph_msgs
+        )
         ",
     )
 }