Add local preference signal scaffolding

docs/progress.md

@@ -7,6 +7,51 @@ Updated: 2026-02-22
 - After every sensible code/documentation change set, create a git commit as
   the last step so the next agent session can pick up from clean checkpoints.
 
+## Latest Milestone (2026-02-22): Local Preference Signal Scaffolding (Inferred/Confirmed)
+
+Added a local-first data model and repository APIs for chat-derived preference
+signals so the app can gradually build profile context from shared messages.
+
+- `lib/features/local/local_models.dart`
+  - new enums:
+    - `PreferenceSignalPolarity` (`like`, `dislike`, `neutral`)
+    - `PreferenceSignalStatus` (`inferred`, `confirmed`, `dismissed`)
+  - new model:
+    - `PersonPreferenceSignal`
+      - key/category/label
+      - confidence
+      - status
+      - first/last seen timestamps
+      - occurrence count
+      - evidence message ids/snippets
+      - source apps
+  - `LocalDataState` now stores `preferenceSignals`
+    - added `copyWith`, `toJson`, `fromJson` support (backward-compatible with
+      existing stored state)
+
+- `lib/features/local/local_repository.dart`
+  - added local-only repository APIs:
+    - `upsertInferredPreferenceSignalObservation(...)`
+      - aggregates repeated observations
+      - merges evidence and source apps
+      - updates confidence and occurrence count
+    - `upsertPreferenceSignal(...)`
+    - `setPreferenceSignalStatus(...)`
+    - `confirmPreferenceSignal(...)`
+    - `dismissPreferenceSignal(...)`
+  - updated person lifecycle consistency:
+    - deleting a person removes linked preference signals
+    - merging profiles rebinds source preference signals to target
+    - remote person delete application also removes preference signals
+  - intentionally local-only for now (not yet mapped to backend sync envelopes)
+
+- `test/features/local/local_repository_test.dart`
+  - added coverage for inferred signal upsert aggregation + status transitions
+
+- Validation
+  - `flutter analyze` -> pass
+  - `flutter test` -> pass
+
 ## Latest Milestone (2026-02-22): Person Editor Inline Validation + Duplicate Warning
 
 Improved the People add/edit profile experience to make validation explicit and