refactor(rules): deduplicate Angular signal state rules

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

shared/rules/angular/references/components-and-state.md

@@ -4,13 +4,7 @@
 * Keep components small; move substantial business logic to a focused service or domain layer.
 * Keep dependencies explicit and follow the feature architecture. Avoid god components, god services, unnecessary wrappers, and abstractions without a concrete need.
 * Use `ChangeDetectionStrategy.OnPush` unless there is a concrete reason not to.
-* Prefer signal-based state for local component state.
-* Prefer `computed` for derived state.
-* Prefer `effect` only for actual side effects.
-* Do not use `effect` as a replacement for normal data flow.
-* Keep component state minimal.
-* Avoid duplicating derived state.
-* Prefer immutable state updates.
+* Keep component state minimal and prefer immutable state updates.
 * Avoid direct mutation of shared state.
 * Keep inputs and outputs strongly typed.
 * Prefer signal-based inputs and outputs when consistent with the project.
@@ -24,13 +18,9 @@
 ## Signals and State
 
 * Prefer signals for local and synchronous reactive state.
-* Prefer `computed` for derived values.
-* Keep signals private when external mutation is not intended.
-* Expose readonly state where practical.
-* Avoid storing values that can be derived from existing state.
+* Derive values with `computed` instead of storing or duplicating them; keep `computed` free of side effects.
+* Keep signals private when external mutation is not intended, and expose readonly state where practical.
 * Avoid circular signal dependencies.
-* Avoid side effects inside `computed`.
-* Keep effects small and deterministic.
-* Clean up resources created by effects.
+* Use `effect` only for actual side effects, not as a replacement for normal data flow. Keep effects small and deterministic, and clean up resources they create.
 * Do not use global state unless multiple unrelated parts of the application genuinely need it.
 * Do not introduce a state-management library without a clear requirement.