Implement remaining Memoirs preset management RPCs

server/migrations/20260516155206_add_user_parts_preset_tags.sql

@@ -0,0 +1,11 @@
+-- +goose Up
+CREATE TABLE user_parts_preset_tags (
+    user_id                       INTEGER NOT NULL REFERENCES users(user_id),
+    user_parts_preset_tag_number  INTEGER NOT NULL,
+    name                          TEXT    NOT NULL DEFAULT '',
+    latest_version                INTEGER NOT NULL DEFAULT 0,
+    PRIMARY KEY (user_id, user_parts_preset_tag_number)
+);
+
+-- +goose Down
+DROP TABLE IF EXISTS user_parts_preset_tags;