fix: detect @angular/platform-server to determine if Angular project uses SSR

[swseverance]

Per #10362 a "SSR warning" message appears when performing firebase init hosting in Angular workspaces that do not use SSR. Now, the discover function for the Angular framework checks for the presence of @angular/platform-server in installed dependencies.

Description

This fix will prevent the following warning from being displayed in Angular workspaces that have no dependencies on @angular/ssr:

Detected a Angular codebase with SSR features. We can't guarantee that this site will work on Firebase Hosting, which is
optimized for static sites. Another product, Firebase App Hosting, was designed for SSR web apps. Would you like to use App
Hosting instead? Learn more here: https://firebase.google.com/docs/app-hosting/product-comparison#hostings

I know personally the first time I saw the warning message (in my codebase with no SSR) it made me think I had incorrectly initialized my Angular workspace to in fact use SSR.

Scenarios Tested

Scenario 1: SSR

1. Create new workspace with SSR

ng new ssr --style css --ssr true --ai-config none
cd ssr

2. Init hosting (this command will differ based upon the user)

node /Users/sam/Documents/firebase-tools/lib/bin/firebase.js init hosting

3. Observe the "SSR warning" appears

Scenario 2: No SSR

1. Create new workspace without SSR

ng new nossr --style css --ssr false --ai-config none
cd nossr

2. Init hosting (this command will differ based upon the user)

node /Users/sam/Documents/firebase-tools/lib/bin/firebase.js init hosting

3. Observe there is no "SSR warning"

Sample Commands

N/A

[gemini-code-assist]

Code Review

This pull request updates the Angular framework discovery logic to detect SSR support by checking for the @angular/ssr dependency. While this correctly identifies Angular 17+ projects, the reviewer pointed out that it misses older versions (16 and below) that rely on @angular/platform-server. To avoid regressions where older SSR projects are incorrectly identified as static, it is recommended to check for @angular/platform-server instead, as it is the core dependency for SSR across all Angular versions.

[annajowang]

lgtm once review comments are addressed

[swseverance]

@annajowang I made the suggested changes and force pushed. Thank you