DRY pass #2, batch 8: the Rust and ffi docs (#5372)

sync/mod.rs listed 5 of its 9 modules; migrate's doc sat above the v9 SQL;
client.rs had items after its test module; the ffi's sync_now doc had fused
into client_update's; complete_reminder (ffi and EditorAction) still said
recurrence advancement was to come, though the core does it; NoteQuery.view
listed views the core never matched and claimed it validated. Test scratch
dirs drop the old ts-/iw- prefixes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

core/src/sync/client.rs

@@ -594,75 +594,6 @@ fn describe_transport_error(base_url: &str, err: &reqwest::Error) -> String {
     }
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn a_share_names_a_person_or_a_group() {
-        assert_eq!(
-            ShareTarget::Member("u1".into()).body("view"),
-            serde_json::json!({ "user_id": "u1", "permission": "view" })
-        );
-        assert_eq!(
-            ShareTarget::Group("g1".into()).body("edit"),
-            serde_json::json!({ "group_id": "g1", "permission": "edit" })
-        );
-        let raw = r#"{"id":"s2","member":null,
-                      "group":{"id":"g1","name":"Family","member_count":3},
-                      "permission":"edit"}"#;
-        let share: NoteShare = serde_json::from_str(raw).expect("a group share reads");
-        assert!(share.member.is_none());
-        assert_eq!(share.group.expect("group").member_count, 3);
-        // A server from before groups sends no `groups` at all.
-        let older: Directory = serde_json::from_str(r#"{"members":[]}"#).expect("directory");
-        assert!(older.groups.is_empty());
-    }
-
-    #[test]
-    fn urls_join_without_doubling_slashes() {
-        // normalize_base_url has already stripped any trailing slash, so plain
-        // concatenation is correct — this pins that assumption.
-        assert_eq!(
-            config_url("https://notes.example.com"),
-            "https://notes.example.com/api/config"
-        );
-        assert_eq!(
-            device_login_url("https://notes.example.com"),
-            "https://notes.example.com/api/auth/device-login"
-        );
-        assert_eq!(
-            me_url("https://notes.example.com"),
-            "https://notes.example.com/api/auth/me"
-        );
-        assert_eq!(
-            revoke_self_url("https://notes.example.com"),
-            "https://notes.example.com/api/auth/devices/self"
-        );
-    }
-
-    #[test]
-    fn revoke_outcome_serializes_tagged_for_the_frontend() {
-        // The UI decides between "signed out on the server" and "still valid, go
-        // revoke it" by reading this tag, so its shape is part of the contract.
-        let json = serde_json::to_string(&RevokeOutcome::Failed {
-            reason: "offline".into(),
-        })
-        .expect("outcome serializes");
-        assert!(json.contains("\"status\":\"failed\""), "got {json}");
-        let json = serde_json::to_string(&RevokeOutcome::Revoked).expect("outcome serializes");
-        assert!(json.contains("\"status\":\"revoked\""), "got {json}");
-    }
-
-    #[test]
-    fn urls_preserve_a_port_and_subpath() {
-        assert_eq!(
-            config_url("http://192.168.1.10:8000/inkwell"),
-            "http://192.168.1.10:8000/inkwell/api/config"
-        );
-    }
-}
-
 /// The Android client a linked server can hand out.
 ///
 /// Mirrors `/api/client/android` (see the server's `client_dist.py`). Absent there
@@ -782,3 +713,72 @@ pub async fn download_client(
     std::fs::rename(&partial, dest)
         .map_err(|e| format!("Couldn't put the downloaded update in place: {e}"))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn a_share_names_a_person_or_a_group() {
+        assert_eq!(
+            ShareTarget::Member("u1".into()).body("view"),
+            serde_json::json!({ "user_id": "u1", "permission": "view" })
+        );
+        assert_eq!(
+            ShareTarget::Group("g1".into()).body("edit"),
+            serde_json::json!({ "group_id": "g1", "permission": "edit" })
+        );
+        let raw = r#"{"id":"s2","member":null,
+                      "group":{"id":"g1","name":"Family","member_count":3},
+                      "permission":"edit"}"#;
+        let share: NoteShare = serde_json::from_str(raw).expect("a group share reads");
+        assert!(share.member.is_none());
+        assert_eq!(share.group.expect("group").member_count, 3);
+        // A server from before groups sends no `groups` at all.
+        let older: Directory = serde_json::from_str(r#"{"members":[]}"#).expect("directory");
+        assert!(older.groups.is_empty());
+    }
+
+    #[test]
+    fn urls_join_without_doubling_slashes() {
+        // normalize_base_url has already stripped any trailing slash, so plain
+        // concatenation is correct — this pins that assumption.
+        assert_eq!(
+            config_url("https://notes.example.com"),
+            "https://notes.example.com/api/config"
+        );
+        assert_eq!(
+            device_login_url("https://notes.example.com"),
+            "https://notes.example.com/api/auth/device-login"
+        );
+        assert_eq!(
+            me_url("https://notes.example.com"),
+            "https://notes.example.com/api/auth/me"
+        );
+        assert_eq!(
+            revoke_self_url("https://notes.example.com"),
+            "https://notes.example.com/api/auth/devices/self"
+        );
+    }
+
+    #[test]
+    fn revoke_outcome_serializes_tagged_for_the_frontend() {
+        // The UI decides between "signed out on the server" and "still valid, go
+        // revoke it" by reading this tag, so its shape is part of the contract.
+        let json = serde_json::to_string(&RevokeOutcome::Failed {
+            reason: "offline".into(),
+        })
+        .expect("outcome serializes");
+        assert!(json.contains("\"status\":\"failed\""), "got {json}");
+        let json = serde_json::to_string(&RevokeOutcome::Revoked).expect("outcome serializes");
+        assert!(json.contains("\"status\":\"revoked\""), "got {json}");
+    }
+
+    #[test]
+    fn urls_preserve_a_port_and_subpath() {
+        assert_eq!(
+            config_url("http://192.168.1.10:8000/inkwell"),
+            "http://192.168.1.10:8000/inkwell/api/config"
+        );
+    }
+}