docs: describe AngularFire 21 as released, not as a release candidate (#3814)

Same change as #3813 on 21.0.x, carried to main because the public
announcements and the rc.1 release notes link the upgrade guide at
blob/main, so main's copy must read the same once 21.0.0 is on latest.
The AI-agent note goes too: its fix (#3769) has been on main since rc.2.

The upgrade command keeps @angular/fire unversioned: only the first
@angular/ package in an ng update command picks the CLI that runs it.

(cherry picked from commit ca70d4c)

Author: armando-navarro

README.md

@@ -5,7 +5,7 @@ AngularFire smooths over the rough edges an Angular developer might encounter wh
 [Firebase JS SDK](https://github.com/firebase/firebase-js-sdk) & aims to provide a more natural developer experience
 by conforming to Angular conventions.
 
-<strong><pre>ng add @angular/fire@next</pre></strong>
+<strong><pre>ng add @angular/fire</pre></strong>
 
 - **Dependency injection** - Provide and Inject Firebase services in your components.
 - **Zone.js wrappers** - Stable zones allow proper functionality of service workers, forms, SSR, and pre-rendering.

docs/install-and-setup.md

@@ -4,10 +4,8 @@
 
 - **Firebase CLI**
   - Setup uses the Firebase CLI (`firebase-tools`). Install it with `npm install -g firebase-tools`, then run `firebase login`. If `ng add` can't find a copy, it installs the newest version for you.
-  - Run `ng add` yourself, not through an AI agent.
-    - In AngularFire 21.0.0-rc.1 and earlier, `ng add` run by an agent with firebase-tools 15.26 or later stops after you choose features, with `Cannot read properties of undefined (reading 'email')`.
-    - If it already stopped, run `ng add @angular/fire@next` again yourself. The stopped run leaves only an empty `firebase.json`, which the second run reuses.
   - A copy older than 14 stops setup with `firebase-tools version 14.0.0+ is required, please upgrade and run again`, and `ng add` does not upgrade a copy you already have.
+  - If `ng add` stops before finishing, run it again. A stopped run leaves only an empty `firebase.json`, which the next run reuses.
 - **npm 11.6 or later**, if you use npm. Older versions, including the npm 10 that ships with Node.js 20 and 22, cannot install a new Angular 21 project ([npm/cli#9787](https://github.com/npm/cli/issues/9787), `Cannot read properties of null (reading 'edgesOut')`). Update with `npm install -g npm@11`.
   - If it already failed, delete the project folder it left behind before running the command again.
 - **Harmless CLI noise.** The Firebase CLI may print a `punycode` deprecation warning or ask about enabling extra features (for example Gemini) during setup. These come from the CLI, not from AngularFire, and are safe to ignore.
@@ -39,10 +37,8 @@ These commands set up an Angular 21 project, the version AngularFire 21 supports
 
 ### 2. Install AngularFire and Firebase
 
-AngularFire 21 is currently a release candidate, published under the `next` tag:
-
 ```bash
-ng add @angular/fire@next
+ng add @angular/fire
 ```
 
 This installs AngularFire and configures your project. `ng add` will:

docs/install-firebase-tools.md

@@ -1,7 +1,5 @@
 # Firebase Tools Install and Setup
 
-> Setting up AngularFire? Run `ng add @angular/fire` yourself, not through an AI agent. In AngularFire 21.0.0-rc.1 and earlier, `ng add` run by an agent with firebase-tools 15.26 or later stops after you choose AngularFire features, with `Cannot read properties of undefined (reading 'email')`.
-
 ### 1. Install package
 
 ```bash

docs/version-21-upgrade.md

@@ -1,13 +1,13 @@
-# Upgrading to the AngularFire 21 Release Candidate
+# Upgrading to AngularFire 21
 
 AngularFire 21 targets **Angular 21** and the **Firebase JS SDK v12**. Most of the upgrade is handled for you by `ng update`.
 
 ## Run the update
 
-The release candidate is published under the `next` tag. From an app on Angular 20 and AngularFire 20, run:
+From an app on Angular 20 and AngularFire 20, run:
 
 ```bash
-ng update @angular/core@21 @angular/cli@21 @angular/fire@next
+ng update @angular/core@21 @angular/cli@21 @angular/fire
 ```
 
 The AngularFire update runs a migration that:
@@ -82,5 +82,5 @@ Two symbols were removed rather than renamed. The migration leaves their imports
 
 - **Angular 21.2 is required.** AngularFire 21 peers `@angular/* ^21.2.0` and does not support Angular 22 (a future AngularFire 22 will).
 - The obsolete `@angular/platform-browser-dynamic` and the unused optional `@angular/platform-server` peer dependencies were removed. No action is needed.
-- **App Check no longer runs during server rendering** (21.0.0-rc.2 and later). `inject(AppCheck)` returns `null` on the server. To keep it running there, provide `APP_CHECK_ON_SERVER` as `true` in your server config. See [App Check during server rendering](./app-check.md#server-side-rendering).
-- **`ng update` can stop with `The Angular CLI requires a minimum Node.js version of ...`.** This happens when the first `@angular/` package in the command has no version number: `ng update` then runs with the newest Angular CLI, which requires a newer Node.js than Angular 21 does. Either update Node.js, or give that package a version number, as the command above does (`ng update @angular/fire@21.0.0-rc.2` for the release candidate, `ng update @angular/fire@21` once 21.0.0 is published).
+- **App Check no longer runs during server rendering** (since 21.0.0-rc.2). `inject(AppCheck)` returns `null` on the server. To keep it running there, provide `APP_CHECK_ON_SERVER` as `true` in your server config. See [App Check during server rendering](./app-check.md#server-side-rendering).
+- **`ng update` can stop with `The Angular CLI requires a minimum Node.js version of ...`.** This happens when the first `@angular/` package in the command has no version number: `ng update` then runs with the newest Angular CLI, which requires a newer Node.js than Angular 21 does. Either update Node.js, or give that package a version number, as the command above does. Updating AngularFire on its own needs the version too: run `ng update @angular/fire@21`, not `ng update @angular/fire`.