SeaORM beside rusqlite: entities, schema sync, a second connection

The first step of moving to SeaORM (#18, phase 1). Nothing a user sees changes.

- src/entity.rs: the seven tables as SeaORM entities, matching the SQLite schema.
  Strings are Text, as the columns are; yes/no columns are bool, which is BOOLEAN
  on Postgres and stays INTEGER in the existing SQLite file (sync notes the
  difference and leaves it alone).
- Db holds a SeaORM connection to the same SQLite file beside the rusqlite one;
  functions move to it one at a time, and rusqlite goes with the last of them.
- db::sync creates what a database is missing from the entities (SeaORM's
  schema-sync, experimental, so sea-orm is pinned to ~2.0), plus the two indexes
  an entity cannot express. Checked against a copy of production: it added the
  lower(name) index and changed nothing else.
- Test databases are now built from the entities alone, in a temporary file
  (two connections to one ":memory:" are two databases), so every test also
  checks that the entities describe what the queries need. That caught the one
  difference: finding a user by name relied on COLLATE NOCASE, which Postgres
  lacks; it now compares lower() on both sides.
- rusqlite steps back to 0.39: 0.40's libsqlite3-sys is newer than sqlx accepts,
  and only one may link SQLite. It goes away at the end of this phase.

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

src/main.rs

@@ -1,6 +1,7 @@
 mod auth;
 mod config;
 mod db;
+mod entity;
 mod download;
 mod feed;
 mod ipc;
@@ -179,7 +180,7 @@ async fn main() -> Result<()> {
 
     let config_path = cli.config.clone().unwrap_or_else(config::config_path);
     let cfg = config::Config::load(&config_path)?;
-    let db = db::Db::open(&config::data_dir().join("state.db"))?;
+    let db = db::Db::open(&config::data_dir().join("state.db")).await?;
 
     // A daemon owns the state; don't have two processes downloading the same thing.
     let wire_cmd = match &cli.command {
@@ -1690,8 +1691,8 @@ mod tests {
         }
     }
 
-    #[test]
-    fn a_shared_feed_is_fetched_for_whoever_wants_the_most() {
+    #[tokio::test]
+    async fn a_shared_feed_is_fetched_for_whoever_wants_the_most() {
         // Nobody subscribed: the feed's own settings stand, as in a single-user install.
         let p = merge_policy(&[], &feed(), 3);
         assert!(p.auto_download);
@@ -1721,10 +1722,10 @@ mod tests {
         assert!(p.auto_download);
     }
 
-    fn test_ctx(cfg: config::Config) -> Ctx {
+    async fn test_ctx(cfg: config::Config) -> Ctx {
         Ctx {
             cfg: std::sync::RwLock::new(Arc::new(cfg)),
-            db: db::Db::memory().unwrap(),
+            db: db::Db::memory().await.unwrap(),
             client: reqwest::Client::new(),
             out: Emitter::terminal(),
             torrents: tokio::sync::OnceCell::new(),
@@ -1734,11 +1735,11 @@ mod tests {
         }
     }
 
-    #[test]
-    fn a_derived_feed_is_not_scanned_once_its_opml_leaves_config() {
+    #[tokio::test]
+    async fn a_derived_feed_is_not_scanned_once_its_opml_leaves_config() {
         // davewiner: the OPML subscription left config.toml, but its 922 derived rows
         // stayed in the database and kept being scanned under the no-parent fallback.
-        let ctx = test_ctx(config::Config::default());
+        let ctx = test_ctx(config::Config::default()).await;
         ctx.db.upsert_managed("child", "http://x/child.xml", "Child", "gone-opml").unwrap();
         assert!(
             subscriptions(&ctx).unwrap().iter().all(|s| s.id != "child"),
@@ -1746,9 +1747,9 @@ mod tests {
         );
     }
 
-    #[test]
-    fn retiring_a_group_drops_what_was_never_downloaded_and_orphans_the_rest() {
-        let ctx = test_ctx(config::Config::default());
+    #[tokio::test]
+    async fn retiring_a_group_drops_what_was_never_downloaded_and_orphans_the_rest() {
+        let ctx = test_ctx(config::Config::default()).await;
         ctx.db.upsert_managed("empty", "http://x/empty.xml", "Empty", "parent").unwrap();
         ctx.db.upsert_managed("has-file", "http://x/has-file.xml", "Has File", "parent").unwrap();
         let enc = feed::Enclosure { url: "http://x/ep.mp3".into(), mime: None, length: None };
@@ -1763,14 +1764,14 @@ mod tests {
         assert!(ctx.db.feed_summary("has-file").unwrap().orphaned, "and flagged as orphaned");
     }
 
-    #[test]
-    fn a_stranded_group_is_retired_but_a_promoted_feed_keeps_its_entries() {
+    #[tokio::test]
+    async fn a_stranded_group_is_retired_but_a_promoted_feed_keeps_its_entries() {
         // davewiner: the OPML left config before retire_group existed, and 11 of its feeds
         // promoted to config since still said managed = 1.
         let mut cfg = config::Config::default();
         cfg.feeds.insert("promoted".into(), feed());
         cfg.feeds.insert("live-opml".into(), feed());
-        let ctx = test_ctx(cfg);
+        let ctx = test_ctx(cfg).await;
         ctx.db.upsert_managed("promoted", "http://x/p.xml", "Promoted", "gone-opml").unwrap();
         ctx.db.upsert_managed("empty", "http://x/e.xml", "Empty", "gone-opml").unwrap();
         ctx.db.upsert_managed("listed", "http://x/l.xml", "Listed", "live-opml").unwrap();