Add local source ingest and podcasts

Marks/Models/IngestedSource.swift

@@ -0,0 +1,69 @@
+import Foundation
+
+enum IngestedSourceKind: String, Codable, Sendable, CaseIterable {
+    case text
+    case pdf
+    case file
+
+    var label: String {
+        switch self {
+        case .text: "Text"
+        case .pdf: "PDF"
+        case .file: "File"
+        }
+    }
+}
+
+struct IngestedSource: Identifiable, Codable, Sendable, Hashable {
+    let id: UUID
+    var kind: IngestedSourceKind
+    var title: String
+    var bodyText: String
+    var originalFilename: String?
+    var localFilename: String?
+    var tags: [String]
+    var createdAt: Date
+    var modifiedAt: Date
+
+    init(
+        id: UUID = UUID(),
+        kind: IngestedSourceKind,
+        title: String,
+        bodyText: String,
+        originalFilename: String? = nil,
+        localFilename: String? = nil,
+        tags: [String] = [],
+        createdAt: Date = Date(),
+        modifiedAt: Date = Date()
+    ) {
+        self.id = id
+        self.kind = kind
+        self.title = title
+        self.bodyText = bodyText
+        self.originalFilename = originalFilename
+        self.localFilename = localFilename
+        self.tags = tags
+        self.createdAt = createdAt
+        self.modifiedAt = modifiedAt
+    }
+
+    var displayTitle: String {
+        let trimmed = title.trimmingCharacters(in: .whitespacesAndNewlines)
+        if !trimmed.isEmpty { return trimmed }
+        return originalFilename ?? kind.label
+    }
+
+    var excerpt: String {
+        bodyText
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+            .replacingOccurrences(of: "\n", with: " ")
+    }
+
+    var podcastURL: String {
+        "marks-source://\(id.uuidString)"
+    }
+
+    var podcastText: String {
+        String(bodyText.trimmingCharacters(in: .whitespacesAndNewlines).prefix(100_000))
+    }
+}