feat(widget): per-residence widget configuration (iOS, gitea#6)

Users with multiple residences can now pick which one a given home-
screen widget shows tasks for. Pinning two widgets — one per house —
lets each surface tasks for only that residence; users who keep the
configuration untouched continue to see all residences (the previous
default), so single-home users see no behavioural change.

Implementation (iOS only — Android Glance follow-up is scoped in the
issue):

* `ConfigurationAppIntent` (HoneyDue widget extension) gains an
  optional `@Parameter` of type `WidgetResidenceEntity`. `AppIntents`
  renders it as a residence picker in the widget edit sheet.
* `WidgetResidenceEntity` + `WidgetResidenceEntityQuery` resolve the
  user's residences from a new `widget_residences.json` sidecar in the
  App Group container (avoids a network call at config time).
* `WidgetDataManager.saveResidences(from:)` writes that sidecar from
  the main app whenever `DataManagerObservable.myResidences` updates.
  Logout clears it along with the rest of the widget cache.
* `WidgetDataManager.WidgetTask` + the widget extension's
  `CacheManager.CustomTask` both gain an optional `residence_id`
  field. Optional so older app builds that wrote pre-#6 widget cache
  continue to decode — those tasks pass through the filter for
  unscoped widgets and are hidden from scoped ones (safer than
  guessing).
* `CacheManager.getUpcomingTasks(forResidenceId:)` and the pure
  helper `WidgetDataManager.filterTasks(_:forResidenceId:)` apply the
  filter. `Provider.timeline` / `snapshot` read
  `configuration.residence?.intId` and pass it through.

Tests: new `WidgetResidenceFilterTests` (HoneyDueTests target, 5
cases) cover nil-passthrough, matching-id, no-match, missing-residence
on a task, and order preservation. All five green.

No Android changes in this commit — Glance widgets need a separate
configuration activity and an actionStartActivity wiring that's
non-trivial; tracking as a follow-up in the same issue.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

iosApp/HoneyDue/AppIntent.swift

@@ -10,9 +10,79 @@ import AppIntents
 import Foundation
 
 // MARK: - Widget Configuration Intent
+
+/// Per-instance widget configuration. The `residence` parameter (added
+/// for gitea#6) lets users with multiple residences pick which one a
+/// given widget tile shows tasks for. When unset the widget continues
+/// to display tasks across every residence — that's the single-home
+/// default and matches pre-#6 behaviour for users who only have one
+/// property.
 struct ConfigurationAppIntent: WidgetConfigurationIntent {
     static var title: LocalizedStringResource { "honeyDue Configuration" }
-    static var description: IntentDescription { "Configure your honeyDue widget" }
+    static var description: IntentDescription {
+        IntentDescription("Pick which residence this widget shows tasks for.")
+    }
+
+    @Parameter(title: "Residence")
+    var residence: WidgetResidenceEntity?
+}
+
+// MARK: - Residence Entity (configuration picker)
+
+/// `AppEntity` exposing the user's residences to the widget's
+/// configuration sheet. Reads from the `widget_residences.json`
+/// sidecar that the main app writes via
+/// `WidgetDataManager.saveResidences(...)`.
+struct WidgetResidenceEntity: AppEntity, Identifiable, Hashable {
+    /// Backing residence id (matches `Residence.id` on the server). Stored
+    /// as `String` because `AppEntity.id` requires `Hashable`-conformance
+    /// for stable widget reconfiguration — Apple's docs recommend a stable
+    /// string identifier over `Int` so the widget timeline survives
+    /// device-id changes.
+    var id: String
+
+    var name: String
+
+    /// Convenience integer form for `CacheManager.getUpcomingTasks`.
+    var intId: Int? { Int(id) }
+
+    static var typeDisplayRepresentation: TypeDisplayRepresentation {
+        TypeDisplayRepresentation(name: "Residence")
+    }
+
+    var displayRepresentation: DisplayRepresentation {
+        DisplayRepresentation(title: "\(name)")
+    }
+
+    static var defaultQuery = WidgetResidenceEntityQuery()
+}
+
+/// Provides the residence choices the configuration sheet displays. The
+/// list is sourced from the App-Group-shared `widget_residences.json`
+/// the main app maintains; on a brand-new install (or signed-out state)
+/// the sheet falls back to showing only the "All residences" implicit
+/// option exposed by the optional parameter.
+struct WidgetResidenceEntityQuery: EntityQuery {
+    /// Look up specific residences by id (used when the system needs to
+    /// re-resolve a saved configuration after the user reopens the
+    /// widget edit sheet).
+    func entities(for identifiers: [WidgetResidenceEntity.ID]) async throws -> [WidgetResidenceEntity] {
+        let known = loadAll()
+        return identifiers.compactMap { id in known.first(where: { $0.id == id }) }
+    }
+
+    /// Populate the picker. Sorted alphabetically so the list is stable
+    /// across refreshes — `WidgetDataManager.saveResidences` writes in
+    /// the order the API returned, which can shuffle on server-side
+    /// re-sorts.
+    func suggestedEntities() async throws -> [WidgetResidenceEntity] {
+        loadAll().sorted { $0.name.localizedCaseInsensitiveCompare($1.name) == .orderedAscending }
+    }
+
+    private func loadAll() -> [WidgetResidenceEntity] {
+        let raw = CacheManager.getResidences()
+        return raw.map { WidgetResidenceEntity(id: String($0.id), name: $0.name) }
+    }
 }
 
 // MARK: - Complete Task Intent