export: bring matched items up to date on every run

Export matched each item against the target and then skipped it, so a second
run -- the usual final pass of a cutover -- never carried anything that had
changed at the source since the first: read and flagged state, moves between
folders, edited contacts, events and Sieve scripts. It reported them as
skipped and exited 0, while the usage guide said matched items were updated.

Matched items are now updated, with one batched /set per type:

- Email: keywords are set to the archive's, added and removed, compared
  case-insensitively. Memberships of folders this run migrated are added and
  removed to match; folders that exist only on the target are left alone,
  and a message is never left in no folder. Properties the server did not
  report are not touched.
- Contacts and events: when both copies carry `updated`, the archive's is
  written only if it is newer; otherwise each property the archive writes is
  compared, and those that differ are sent whole.
- Sieve scripts: the target's copy is downloaded and compared byte for byte,
  and replaced with the archive's when it differs.

Updated items are counted as `updated`; unchanged ones stay `skipped`. The
usage guide now describes this.

tests/mock_sync.rs

@@ -2575,7 +2575,7 @@ fn export_archive_read_failure_while_inlining_exits_seven() {
 }
 
 #[test]
-fn export_sieve_script_matches_by_name_not_content() {
+fn export_sieve_script_matched_by_name_is_updated_when_its_content_differs() {
     let mut server = mockito::Server::new();
     let base = server.url();
     let api = "/jmap/api";
@@ -2615,9 +2615,125 @@ fn export_sieve_script_matches_by_name_not_content() {
         )
         .expect(1)
         .create();
-    let no_download = server
+    let download = server
         .mock("GET", Matcher::Regex("/jmap/dl/w/BSRV/.*".into()))
-        .with_body(b"unused".as_slice())
+        .with_body(b"keep;\n".as_slice())
+        .expect(1)
+        .create();
+    let upload = server
+        .mock("POST", Matcher::Regex("/jmap/upload/".into()))
+        .with_body(json!({"blobId":"UPN"}).to_string())
+        .expect(2)
+        .create();
+    let update = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("SieveScript/set".into()),
+            Matcher::Regex("\"update\":\\{\"S1\":\\{\"blobId\":\"UPN\"".into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["SieveScript/set",{"accountId":"w",
+                "updated":{"S1":null}},"s"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let create = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("SieveScript/set".into()),
+            Matcher::Regex("reject".into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["SieveScript/set",{"accountId":"w",
+                "created":{"c2":{"id":"S2"}}},"s"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _activate = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("onSuccessActivateScript".into()))
+        .with_body(
+            json!({"methodResponses":[["SieveScript/set",{"accountId":"w"},"a"]]}).to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let summary = sync::export::run(
+        common(&archive),
+        export_cfg_objects(&base, vec![ObjectType::SieveScript]),
+    )
+    .expect("export");
+    upload.assert();
+    create.assert();
+    download.assert();
+    update.assert();
+    let counts = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "SieveScript")
+        .map(|(_, c)| c.clone())
+        .expect("sieve counts");
+    assert_eq!(
+        counts.updated, 1,
+        "the name-matched script gets the archive's content"
+    );
+    assert_eq!(counts.skipped, 0);
+    assert_eq!(counts.created, 1, "the unmatched name is created");
+    assert_eq!(counts.failed, 0);
+    let _ = std::fs::remove_file(&archive);
+}
+
+#[test]
+fn export_sieve_script_matched_by_name_with_the_same_content_is_left_alone() {
+    let mut server = mockito::Server::new();
+    let base = server.url();
+    let api = "/jmap/api";
+    let archive = tmp();
+    let keepall_local = b"require [\"fileinto\"];\nkeep;\n";
+    let reject_local = b"require [\"reject\"];\nreject \"go away\";\n";
+    {
+        let conn = db::init::open(&archive).unwrap();
+        let blob1 = db::blobs::intern_blob(&conn, keepall_local).unwrap();
+        let blob2 = db::blobs::intern_blob(&conn, reject_local).unwrap();
+        conn.execute(
+            "INSERT INTO sieve_scripts (id,name,is_active,blob_id) VALUES (1,'keepall',1,?1)",
+            rusqlite::params![blob1],
+        )
+        .unwrap();
+        conn.execute(
+            "INSERT INTO sieve_scripts (id,name,is_active,blob_id) VALUES (2,'reject',0,?1)",
+            rusqlite::params![blob2],
+        )
+        .unwrap();
+    }
+
+    let _root = server.mock("GET", "/").with_status(404).create();
+    let _wk = server
+        .mock("GET", "/.well-known/jmap")
+        .with_body(session_body_full(&base))
+        .expect_at_least(1)
+        .create();
+    let _g = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("SieveScript/get".into()))
+        .with_body(
+            json!({"methodResponses":[["SieveScript/get",{"accountId":"w","list":[
+                {"id":"S1","name":"keepall","isActive":false,"blobId":"BSRV"}
+            ],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let download = server
+        .mock("GET", Matcher::Regex("/jmap/dl/w/BSRV/.*".into()))
+        .with_body(keepall_local.as_slice())
+        .expect(1)
+        .create();
+    let no_update = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("\"update\"".into()))
         .expect(0)
         .create();
     let upload = server
@@ -2654,7 +2770,8 @@ fn export_sieve_script_matches_by_name_not_content() {
     .expect("export");
     upload.assert();
     create.assert();
-    no_download.assert();
+    download.assert();
+    no_update.assert();
     let counts = summary
         .per_type
         .iter()
@@ -2663,8 +2780,9 @@ fn export_sieve_script_matches_by_name_not_content() {
         .expect("sieve counts");
     assert_eq!(
         counts.skipped, 1,
-        "name-matched script is skipped even though its content differs from the target"
+        "same name and same content: nothing to do"
     );
+    assert_eq!(counts.updated, 0);
     assert_eq!(counts.created, 1, "the unmatched name is created");
     assert_eq!(counts.failed, 0);
     let _ = std::fs::remove_file(&archive);
@@ -4701,3 +4819,175 @@ fn export_different_messages_sharing_a_message_id_are_not_merged() {
     no_set.assert();
     let _ = std::fs::remove_file(&archive);
 }
+
+#[test]
+fn export_rerun_carries_a_read_flag_set_at_the_source() {
+    let mut server = mockito::Server::new();
+    let base = server.url();
+    let api = "/jmap/api";
+    let archive = tmp();
+    let _setup = two_folder_archive_and_target(&mut server, &archive);
+    insert_email_copy(&archive, ONE_MESSAGE, 1);
+    {
+        let conn = db::init::open(&archive).unwrap();
+        conn.execute("UPDATE emails SET keywords='[\"$seen\"]'", [])
+            .unwrap();
+    }
+
+    let _eq = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Email/query".into()))
+        .with_body(
+            json!({"methodResponses":[["Email/query",{"accountId":"w","ids":["X1"]},"q"]]})
+                .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _eg = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("Email/get".into()))
+        .with_body(
+            json!({"methodResponses":[["Email/get",{"accountId":"w","list":[
+                {"id":"X1","messageId":["both@h"],"size":ONE_MESSAGE.len(),
+                 "mailboxIds":{"T1":true},"keywords":{"$flagged":true}}
+            ],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let set = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("Email/set".into()),
+            Matcher::Regex("\"keywords/\\$seen\":true".into()),
+            Matcher::Regex("\"keywords/\\$flagged\":null".into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["Email/set",{"accountId":"w","updated":{"X1":null}},"s"]]})
+                .to_string(),
+        )
+        .expect(1)
+        .create();
+
+    let summary = sync::export::run(
+        common(&archive),
+        export_cfg_objects(&base, vec![ObjectType::Mailbox, ObjectType::Email]),
+    )
+    .expect("export");
+    let email = email_counts(&summary);
+    assert_eq!(email.updated, 1);
+    assert_eq!(email.created, 0);
+    assert_eq!(email.failed, 0);
+    set.assert();
+    let _ = std::fs::remove_file(&archive);
+}
+
+fn contact_rerun(local_updated: &str, updates_sent: usize) -> inbuxa_migrate::sync::TypeCounts {
+    let mut server = mockito::Server::new();
+    let base = server.url();
+    let api = "/jmap/api";
+    let archive = tmp();
+    {
+        let conn = db::init::open(&archive).unwrap();
+        conn.execute(
+            "INSERT INTO address_books (id,name,description,is_default) VALUES (1,'Personal',NULL,1)",
+            [],
+        )
+        .unwrap();
+        let card = json!({"@type":"Card","version":"1.0","uid":"u1",
+                          "name":{"full":"Ann Brown"},"updated":local_updated});
+        conn.execute(
+            "INSERT INTO contact_cards (id,uid,address_book_ids,data) VALUES (1,'u1','[1]',?1)",
+            rusqlite::params![card.to_string()],
+        )
+        .unwrap();
+    }
+    let _root = server.mock("GET", "/").with_status(404).create();
+    let _wk = server
+        .mock("GET", "/.well-known/jmap")
+        .with_body(session_body_full(&base))
+        .expect_at_least(1)
+        .create();
+    let _abg = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("AddressBook/get".into()))
+        .with_body(
+            json!({"methodResponses":[["AddressBook/get",{"accountId":"w","list":[
+                {"id":"P","name":"Personal","isDefault":true,"myRights":{"mayDelete":false}}
+            ],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect_at_least(1)
+        .create();
+    let _term = anchor_terminator(&mut server, api, "ContactCard");
+    let _cq = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("ContactCard/query".into()))
+        .with_body(
+            json!({"methodResponses":[["ContactCard/query",{"accountId":"w","ids":["C1"]},"q"]]})
+                .to_string(),
+        )
+        .expect(1)
+        .create();
+    let _cg = server
+        .mock("POST", api)
+        .match_body(Matcher::Regex("ContactCard/get".into()))
+        .with_body(
+            json!({"methodResponses":[["ContactCard/get",{"accountId":"w","list":[
+                {"id":"C1","@type":"Card","version":"1.0","uid":"u1",
+                 "name":{"full":"Ann"},"addressBookIds":{"P":true},
+                 "updated":"2026-02-01T00:00:00Z"}
+            ],"notFound":[]},"g"]]})
+            .to_string(),
+        )
+        .expect(1)
+        .create();
+    let update = server
+        .mock("POST", api)
+        .match_body(Matcher::AllOf(vec![
+            Matcher::Regex("ContactCard/set".into()),
+            Matcher::Regex("\"update\"".into()),
+            Matcher::Regex("Ann Brown".into()),
+        ]))
+        .with_body(
+            json!({"methodResponses":[["ContactCard/set",{"accountId":"w","updated":{"C1":null}},"s"]]})
+                .to_string(),
+        )
+        .expect(updates_sent)
+        .create();
+
+    let summary = sync::export::run(
+        common(&archive),
+        export_cfg_objects(
+            &base,
+            vec![ObjectType::AddressBook, ObjectType::ContactCard],
+        ),
+    )
+    .expect("export");
+    let counts = summary
+        .per_type
+        .iter()
+        .find(|(t, _)| *t == "ContactCard")
+        .map(|(_, c)| c.clone())
+        .expect("contact counts");
+    update.assert();
+    let _ = std::fs::remove_file(&archive);
+    counts
+}
+
+#[test]
+fn export_rerun_updates_a_contact_edited_at_the_source() {
+    let counts = contact_rerun("2026-03-01T00:00:00Z", 1);
+    assert_eq!(counts.updated, 1, "the newer archive copy is written");
+    assert_eq!(counts.failed, 0);
+}
+
+#[test]
+fn export_rerun_leaves_a_contact_alone_when_the_target_is_newer() {
+    let counts = contact_rerun("2026-01-01T00:00:00Z", 0);
+    assert_eq!(
+        counts.updated, 0,
+        "the target's copy is newer, so nothing is sent"
+    );
+    assert_eq!(counts.skipped, 1);
+}