feat: generate AI titles and summaries for Mac-authored notes

ios/Keep/Models/Note.swift

@@ -37,3 +37,8 @@ struct Note: Identifiable, Codable, Equatable {
 struct NotesResponse: Codable { let notes: [Note] }
 struct NoteResponse: Codable { let note: Note }
 struct OkResponse: Codable { let ok: Bool }
+/// POST /api/notes/title — model-generated (or heuristic) note metadata.
+struct NoteMeta: Codable {
+    let title: String
+    let summary: String?
+}

ios/Keep/Services/KeepAPI.swift

@@ -36,14 +36,25 @@ actor KeepAPI {
         try await request("/api/notes", method: "GET", as: NotesResponse.self).notes
     }
 
-    func create(body: String) async throws -> Note {
-        try await request(
+    func create(body: String, title: String? = nil, summary: String? = nil) async throws -> Note {
+        var json: [String: Any] = ["body": body]
+        if let title { json["title"] = title }
+        if let summary, !summary.isEmpty { json["summary"] = summary }
+        return try await request(
             "/api/notes", method: "POST",
-            json: ["body": body],
+            json: json,
             as: NoteResponse.self
         ).note
     }
 
+    func generateMeta(body: String) async throws -> NoteMeta {
+        try await request(
+            "/api/notes/title", method: "POST",
+            json: ["body": body],
+            as: NoteMeta.self
+        )
+    }
+
     func update(id: String, patch: [String: Any]) async throws -> Note {
         try await request(
             "/api/notes/\(id)", method: "PATCH",

ios/Keep/Services/NotesStore.swift

@@ -41,7 +41,8 @@ final class NotesStore {
     @discardableResult
     func create(body: String) async -> Note? {
         do {
-            let note = try await api.create(body: body)
+            let meta = try? await api.generateMeta(body: body)
+            let note = try await api.create(body: body, title: meta?.title, summary: meta?.summary)
             notes.insert(note, at: 0)
             return note
         } catch {
@@ -50,13 +51,31 @@ final class NotesStore {
         }
     }
 
+    /// Body saves regenerate the title/summary when the lead line changes (or
+    /// the note has no title yet), folded into the same PATCH — mirroring the
+    /// web's autosave. Meta failures degrade to a plain body save.
     func update(_ id: String, patch: [String: Any]) async {
+        var patch = patch
+        if let body = patch["body"] as? String,
+           patch["title"] == nil,
+           let current = notes.first(where: { $0.id == id }),
+           Self.firstLine(body) != Self.firstLine(current.body)
+               || current.title.trimmingCharacters(in: .whitespaces).isEmpty,
+           let meta = try? await api.generateMeta(body: body) {
+            patch["title"] = meta.title
+            if let summary = meta.summary, !summary.isEmpty { patch["summary"] = summary }
+        }
         do {
             let updated = try await api.update(id: id, patch: patch)
             if let i = notes.firstIndex(where: { $0.id == id }) { notes[i] = updated }
         } catch { handle(error) }
     }
 
+    private static func firstLine(_ body: String) -> String {
+        (body.components(separatedBy: "\n").first ?? "")
+            .trimmingCharacters(in: .whitespaces)
+    }
+
     func togglePin(_ note: Note) async {
         await update(note.id, patch: ["pinned": !note.pinned])
     }