clarify guidance; update ADR 0003

Author: willmartian

docs/architecture/adr/0003-observable-data-services.md

@@ -33,6 +33,14 @@ Chosen option: **Observable data services**, because
 - The work towards a reactive data model will allow us to adopt patterns like NGRX in the future
   should it be needed.
 
+:::info Updated Guidance
+
+This ADR remains valid for business logic services, but
+[ADR 0029](/architecture/adr/0029-angular-signals) introduces Angular Signals as the preferred
+approach over RxJS for view layer code (components, directives, pipes, and UI-coupled services).
+
+:::
+
 ### Example
 
 #### Organizations

docs/architecture/adr/0029-angular-signals.md

@@ -32,9 +32,9 @@ linting:
 - `@Output()` → `output()`
 - `@ViewChild`/`@ContentChild` → `viewChild()`/`contentChild()`
 
-Services tightly coupled to Angular should use signals. Services with business logic should prefer
-RxJS for portability. Use `toSignal()` and `toObservable()` to bridge between RxJS and signals when
-necessary.
+Services tightly coupled to Angular should use signals. Services with non-presentational business
+logic should prefer RxJS for portability. Use `toSignal()` and `toObservable()` to bridge between
+RxJS and signals when necessary.
 
 ## Implementation Plan
 
@@ -46,6 +46,10 @@ automatic code migrations for signal
 Much of `libs/components` was updated using these migrators:
 https://github.com/bitwarden/clients/pull/15340
 
+See the
+[Angular Modernization Guide](https://contributing.bitwarden.com/contributing/code-style/web/angular-migration-guide/#signals)
+for more information.
+
 ## Consequences
 
 **Positive:**