Add ESLint rule to prevent Observable-returning method calls in the async pipe (#5933)

[Aryakoste]

References

• Fixes Introduce ESLint rule to prevent Observable-return methods from being used in Angular templates #5933

We commonly call a component method directly as the input of the async pipe in templates, e.g. {{ getFoo$() | async }}. Because the method runs as part of template evaluation, Angular re-executes the whole RxJS pipeline (subscribe + unsubscribe) on every change-detection cycle instead of once — a real, recurring perf issue in this codebase (confirmed instances in audit-table, ePerson-data, and section-coar-notify components).

This PR adds a new dspace-angular-html ESLint rule, no-method-call-with-async-pipe, that flags this pattern anywhere it appears in a template — interpolations, bound attributes/events, @if/@for/@switch blocks, @defer triggers, @let, and object/array literals or optional-chaining wrapped around the pipe.

• New rule: lint/src/rules/html/no-method-call-with-async-pipe.ts
• Registered in lint/src/rules/html/index.ts and enabled in .eslintrc.json
• Docs auto-generated via npm run docs:lint (docs/lint/html/index.md, docs/lint/html/rules/no-method-call-with-async-pipe.md)

Implementation note

The straightforward approach — an ESLint selector like BindingPipe[name="async"] > Call — turned out to miss common real-world cases, because @angular-eslint/template-parser's own visitor-keys map doesn't cover every expression AST node type (e.g. SafePropertyRead, LiteralMap), so ESLint's traversal silently stops before reaching calls wrapped in things like (getFoo$() | async)?.length or [ngClass]="{x: getFoo$() | async}". To get full, correct coverage, the rule instead walks each template expression with @angular/compiler's own RecursiveAstVisitor, which handles every AST node type regardless of that gap.

This rule does not attempt to fix existing offending call sites — per the issue, migrating those (subscribe in ngOnInit(), push into a BehaviorSubject, | async on that, unsubscribe in ngOnDestroy()) is a separate follow-up. The rule is not auto-fixable, since that migration can't be done mechanically.

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[lgeggleston]

Thank you for the PR @Aryakoste! You may have already seen this, but looks like this is failing a few build tests that will need to be addressed.

[ybnd]

Good catch on those selectors, I wasn't aware of that!

[ybnd]

↑ those CI failures are due to the new lint rule

This rule does not attempt to fix existing offending call sites — per the issue, migrating those (...) is a separate follow-up.
The rule is not auto-fixable, since that migration can't be done mechanically.

It won't be possible to auto-fix, but we'll still need to sort out that "follow up step" within this PR as we did in previous PRs that introduced new configuration or rules.