Update Models, Protocols, Services + tests + docs

Summary:
- Sources: Models, Protocols, Services
- Tests: LocalDataTests.swift
- Docs: FutureEnhancements, README
- Added symbols: struct AnyStorageKey, struct StorageKeyDescriptor, protocol StorageKey, func registerCatalog, func validateUniqueKeys, func validateDescription
- Removed symbols: struct StorageKeyDescriptor, struct StorageKeyEntry, protocol StorageKey, func registerCatalog

Stats:
- 11 files changed, 85 insertions(+), 27 deletions(-)

FutureEnhancements.md

@@ -0,0 +1,14 @@
+# Future Enhancements
+
+## Dynamic Key Names
+
+LocalData currently enforces exact, statically-registered key names for auditability.
+If we decide to allow dynamic names later (e.g., per-account keys), the suggested design is:
+
+- Add a name rule type (e.g., `StorageKeyNameRule`) that supports `exact` and `prefix` matching.
+- Extend `StorageKeyEntry` to carry a name rule.
+- Update catalog registration to validate overlapping rules and duplicates.
+- Update `StorageRouter` validation to accept keys that match the registered rules.
+- Require a catalog entry that documents the dynamic name pattern and rationale.
+
+This keeps audit behavior explicit while allowing a controlled, documented escape hatch.

README.md

@@ -159,10 +159,10 @@ LocalData can generate a catalog of all configured storage keys, even if no data
 
 ```swift
 struct AppStorageCatalog: StorageKeyCatalog {
-    static var allKeys: [StorageKeyEntry] {
+    static var allKeys: [AnyStorageKey] {
         [
-            StorageKeyEntry(StorageKeys.AppVersionKey()),
+            .key(StorageKeys.AppVersionKey()),
-            StorageKeyEntry(StorageKeys.UserPreferencesKey())
+            .key(StorageKeys.UserPreferencesKey())
         ]
     }
 }
@@ -175,13 +175,18 @@ let report = StorageAuditReport.renderText(for: AppStorageCatalog.self)
 print(report)
 ```
 
-3) Register the catalog to enforce usage:
+3) Register the catalog to enforce usage and catch duplicates:
 
 ```swift
-StorageRouter.shared.registerCatalog(AppStorageCatalog.self)
+do {
+    try StorageRouter.shared.registerCatalog(AppStorageCatalog.self)
+} catch {
+    assertionFailure("Storage catalog registration failed: \(error)")
+}
 ```
 
-For dynamic key names, use a placeholder name and a note to describe how it is generated.
+Dynamic key names are intentionally not supported in the core API to keep storage auditing strict and predictable.
+If you need this later, see `FutureEnhancements.md` for a proposed design.
 
 ## Sample App
 See `SecureStorgageSample` for working examples of all storage domains and security options.

Sources/LocalData/Models/AnyStorageKey.swift

@@ -0,0 +1,11 @@
+public struct AnyStorageKey: Sendable {
+    public let descriptor: StorageKeyDescriptor
+
+    public init<Key: StorageKey>(_ key: Key) {
+        self.descriptor = .from(key)
+    }
+
+    public static func key<Key: StorageKey>(_ key: Key) -> AnyStorageKey {
+        AnyStorageKey(key)
+    }
+}

Sources/LocalData/Models/StorageError.swift

@@ -11,6 +11,8 @@ public enum StorageError: Error {
     case dataTooLargeForSync
     case notFound
     case unregisteredKey(String)
+    case duplicateRegisteredKeys([String])
+    case missingDescription(String)
     // ...
 }
 

Sources/LocalData/Models/StorageKeyDescriptor.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-public struct StorageKeyDescriptor: Sendable {
+public struct StorageKeyDescriptor: Sendable, CustomStringConvertible {
     public let name: String
     public let domain: StorageDomain
     public let security: SecurityPolicy
@@ -9,7 +9,7 @@ public struct StorageKeyDescriptor: Sendable {
     public let owner: String
     public let availability: PlatformAvailability
     public let syncPolicy: SyncPolicy
-    public let notes: String?
+    public let description: String
 
     init(
         name: String,
@@ -20,7 +20,7 @@ public struct StorageKeyDescriptor: Sendable {
         owner: String,
         availability: PlatformAvailability,
         syncPolicy: SyncPolicy,
-        notes: String? = nil
+        description: String
     ) {
         self.name = name
         self.domain = domain
@@ -30,12 +30,11 @@ public struct StorageKeyDescriptor: Sendable {
         self.owner = owner
         self.availability = availability
         self.syncPolicy = syncPolicy
-        self.notes = notes
+        self.description = description
     }
 
     public static func from<Key: StorageKey>(
-        _ key: Key,
+        _ key: Key
-        notes: String? = nil
     ) -> StorageKeyDescriptor {
         StorageKeyDescriptor(
             name: key.name,
@@ -46,7 +45,7 @@ public struct StorageKeyDescriptor: Sendable {
             owner: key.owner,
             availability: key.availability,
             syncPolicy: key.syncPolicy,
-            notes: notes
+            description: key.description
         )
     }
 }

Sources/LocalData/Models/StorageKeyEntry.swift

@@ -1,7 +0,0 @@
-public struct StorageKeyEntry: Sendable {
-    public let descriptor: StorageKeyDescriptor
-
-    public init<Key: StorageKey>(_ key: Key, notes: String? = nil) {
-        self.descriptor = .from(key, notes: notes)
-    }
-}

Sources/LocalData/Protocols/StorageKey.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-public protocol StorageKey: Sendable {
+public protocol StorageKey: Sendable, CustomStringConvertible {
     associatedtype Value: Codable & Sendable
 
     var name: String { get }

Sources/LocalData/Protocols/StorageKeyCatalog.swift

@@ -1,3 +1,3 @@
 public protocol StorageKeyCatalog {
-    static var allKeys: [StorageKeyEntry] { get }
+    static var allKeys: [AnyStorageKey] { get }
 }

Sources/LocalData/Services/StorageAuditReport.swift

@@ -20,9 +20,7 @@ public struct StorageAuditReport: Sendable {
             parts.append("owner=\(item.owner)")
             parts.append("availability=\(string(for: item.availability))")
             parts.append("sync=\(string(for: item.syncPolicy))")
-            if let notes = item.notes, !notes.isEmpty {
+            parts.append("description=\(item.description)")
-                parts.append("notes=\(notes)")
-            }
             return parts.joined(separator: " | ")
         }
         return lines.joined(separator: "\n")

Sources/LocalData/Services/StorageRouter.swift

@@ -25,8 +25,11 @@ public actor StorageRouter: StorageProviding {
 
     /// Registers a catalog of known storage keys for audit and validation.
     /// When registered, all storage operations will verify keys are listed.
-    public func registerCatalog<C: StorageKeyCatalog>(_ catalog: C.Type) {
+    public func registerCatalog<C: StorageKeyCatalog>(_ catalog: C.Type) throws {
-        registeredKeyNames = Set(catalog.allKeys.map { $0.descriptor.name })
+        let entries = catalog.allKeys
+        try validateDescription(entries)
+        try validateUniqueKeys(entries)
+        registeredKeyNames = Set(entries.map { $0.descriptor.name })
     }
     
     // MARK: - StorageProviding Implementation
@@ -106,10 +109,41 @@ public actor StorageRouter: StorageProviding {
     private func validateCatalogRegistration<Key: StorageKey>(for key: Key) throws {
         guard !registeredKeyNames.isEmpty else { return }
         guard registeredKeyNames.contains(key.name) else {
+#if DEBUG
+            assertionFailure("StorageKey not registered in catalog: \(key.name)")
+#endif
             throw StorageError.unregisteredKey(key.name)
         }
     }
 
+    private func validateUniqueKeys(_ entries: [AnyStorageKey]) throws {
+        var exactNames: [String: Int] = [:]
+        var duplicates: [String] = []
+
+        for entry in entries {
+            exactNames[entry.descriptor.name, default: 0] += 1
+        }
+
+        for (name, count) in exactNames where count > 1 {
+            duplicates.append(name)
+        }
+
+        guard duplicates.isEmpty else {
+            throw StorageError.duplicateRegisteredKeys(duplicates.sorted())
+        }
+    }
+
+    private func validateDescription(_ entries: [AnyStorageKey]) throws {
+        let missing = entries
+            .map(\.descriptor)
+            .filter { $0.description.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }
+            .map(\.name)
+
+        guard missing.isEmpty else {
+            throw StorageError.missingDescription(missing.sorted().joined(separator: ", "))
+        }
+    }
+    
     // MARK: - Serialization
     
     private func serialize<Value: Codable & Sendable>(

Tests/LocalDataTests/LocalDataTests.swift

@@ -10,6 +10,7 @@ private struct TestUserDefaultsKey: StorageKey {
     let security: SecurityPolicy = .none
     let serializer: Serializer<String> = .json
     let owner: String = "LocalDataTests"
+    let description: String = "Test-only key for user defaults round-trip."
     let availability: PlatformAvailability = .all
     let syncPolicy: SyncPolicy = .never
 
@@ -27,6 +28,7 @@ private struct TestFileKey: StorageKey {
     let security: SecurityPolicy = .none
     let serializer: Serializer<String> = .json
     let owner: String = "LocalDataTests"
+    let description: String = "Test-only key for file system round-trip."
     let availability: PlatformAvailability = .all
     let syncPolicy: SyncPolicy = .never