Repository: angular
Issue: Support for client hydration for Web Components hydrated in the server.
Labels: area: core,core: hydration

### Which @angular/* package(s) are the source of the bug?

platform-browser, platform-server

### Is this a regression?

No

### Description

First of all, a huge thanks for your continuous efforts in improving SSR and with this new non-destructive hydration feature.

We've been exploring this new feature and have seen promising results. However, we have encounter a big challenge when trying to integrate it with the server hydration of Web Components, specifically with Stencil.

Our Angular components are predominantly composed of elements from our Stencil components library. To improve rendering and mitigate flickering of the Web Components, we've been pre-rendering them using Stencil’s `renderToString` method for server-side hydration. This approach has been effective until now but seems incompatible with Angular's non-destructive hydration. The method takes the entire generated HTML (result from Angular SSR rendering) and renders the Web Components, producing a new full HTML page, which certainly modifies the DOM and triggers the [NG0500](https://angular.io/errors/NG0500) Hydration error. 

We understand that the ideal would be to avoid the DOM manipulation and for that, it would be needed to have some kind of per-component hydration method in Stencil which I think is not available at the moment, and wouldn't be too easy to implement.

I was thinking that a potential resolution might involve implementing a specific hydration method in the Stencil Angular wrapper, allowing hydration via Angular's DOM renderer functions instead of direct HTML generation. However, I think this wouldn't be easy and might essentially be like implementing a full Stencil to Angular compiler rather than just a wrapper.

I these solutions are not possible, we would have to skip the hydration of all the web components with `ngSkipHydration` but I think that doesn't solve the issue and by doing this, we would be losing most of the advantages of having the client hydration. 

This is one of the main issues we are encountering now and preventing us of enabling the non-destructive hydration with `provideClientHydration`. 

While I understand that this might not be a direct issue with Angular and the new hydration feature, any guidance on how this might be resolved or mitigated would be very valuable. Also, I was wondering if there might be a way to facilitate collaboration with Stencil or other Web Component libraries to propose a solution. Actually, are you aware if this issue has been addressed in some way in Lit, or is there a possibility for collaboration with that team?

I've created this [Sandbox](https://codesandbox.io/p/sandbox/angular-ssr-ap-r3s9vc) to reproduce the problem and it would be useful for exploring potential solutions as it hosts the Stencil components in the same environment.
(It should run well on first load, or it can be downloaded as well and run with `./start.sh` script. Basically, it install and build the Stencil components and the Angular wrapper, and then the Angular SSR server)

Thank you for considering this issue, and we look forward to any insights or suggestions you might have.


### Please provide a link to a minimal reproduction of the bug

https://codesandbox.io/p/sandbox/angular-ssr-ap-r3s9vc

### Please provide the exception or error you saw

```true
Error: NG0500: During hydration Angular expected a text node but found a comment node.

Angular expected this DOM:

<my-component _ngcontent-ng-c2448950787="" class="hydrated">
  #text(Click here)  <-- AT THIS LOCATION
  …
</my-component>

Actual DOM is:

<my-component _ngcontent-ng-c2448950787="" class="hydrated">
  <!--  -->  <-- AT THIS LOCATION
  …
</my-component>

Note: attributes are only displayed to better represent the DOM but have no effect on hydration mismatches.

To fix this problem:
  * check the "AppComponent" component for hydration-related issues
  * check to see if your template has valid HTML structure
  * or skip hydration by adding the `ngSkipHydration` attribute to its host node in a template

 Find more at https://angular.io/errors/NG0500
```


### Please provide the environment you discovered this bug in (run `ng version`)

```true
Angular CLI: 16.2.1
Node: 18.13.0
Package Manager: npm 8.19.3
OS: darwin x64

Angular: 16.2.4
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, platform-server
... router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1602.1
@angular-devkit/build-angular   16.2.1
@angular-devkit/core            16.2.1
@angular-devkit/schematics      16.2.1
@angular/cli                    16.2.1
@nguniversal/builders           16.2.0
@nguniversal/express-engine     16.2.0
@schematics/angular             16.2.1
rxjs                            7.8.1
typescript                      5.1.6
zone.js                         0.13.3
```


### Anything else?

_No response_