docs: fix broken links and anchors across documentation

Fix ~30 broken links and anchors across the documentation site, including
incorrect relative paths, mismatched anchor names, zero-width characters
in URLs, and references to renamed or removed headings.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Fredrik Adelöw <freben@spotify.com>

docs/getting-started/config/authentication--old.md

@@ -210,4 +210,4 @@ If you've updated the configuration for your integration, it's likely that the b
 Some helpful links, for if you want to learn more about:
 
 - [Other available integrations](../../integrations/index.md)
-- [Using GitHub Apps instead of a Personal Access Token](../../integrations/github/github-apps.md#docsNav)
+- [Using GitHub Apps instead of a Personal Access Token](../../integrations/github/github-apps.md)

docs/getting-started/config/authentication.md

@@ -236,4 +236,4 @@ If you've updated the configuration for your integration, it's likely that the b
 Some helpful links, for if you want to learn more about:
 
 - [Other available integrations](../../integrations/index.md)
-- [Using GitHub Apps instead of a Personal Access Token](../../integrations/github/github-apps.md#docsNav)
+- [Using GitHub Apps instead of a Personal Access Token](../../integrations/github/github-apps.md)

docs/getting-started/config/database.md

@@ -190,7 +190,7 @@ backend:
       # highlight-remove-end
 ```
 
-[Start the Backstage app](../index.md#2-run-the-backstage-app):
+[Start the Backstage app](../index.md#creating-and-running-a-backstage-application):
 
 ```shell
 yarn start

docs/getting-started/homepage--old.md

@@ -39,7 +39,7 @@ At the end of this tutorial, you can expect:
 Before we begin, make sure
 
 - You have created your own standalone Backstage app using
-  [`@backstage/create-app`](./index.md#1-create-your-backstage-app) and not
+  [`@backstage/create-app`](./index.md#creating-and-running-a-backstage-application) and not
   using a fork of the [backstage](https://github.com/backstage/backstage)
   repository.
 - You do not have an existing homepage, and by default you are redirected to

docs/getting-started/homepage.md

@@ -26,7 +26,7 @@ At the end of this tutorial, you can expect:
 
 Before we begin, make sure
 
-- You have created your own standalone Backstage app using [`@backstage/create-app`](./index.md#1-create-your-backstage-app) and not using a fork of the [backstage](https://github.com/backstage/backstage) repository.
+- You have created your own standalone Backstage app using [`@backstage/create-app`](./index.md#creating-and-running-a-backstage-application) and not using a fork of the [backstage](https://github.com/backstage/backstage) repository.
 - You do not have an existing homepage, and by default you are redirected to Software Catalog when you open Backstage.
 
 Now, let's get started by installing the home plugin and creating a simple homepage for your Backstage app.

docs/getting-started/keeping-backstage-updated.md

@@ -155,7 +155,7 @@ On Node.js 22.21.0+, the Backstage CLI respects the standard `HTTP_PROXY`, `HTTP
 
 On older Node.js versions, the CLI falls back to [global-agent](https://www.npmjs.com/package/global-agent) and `undici` for proxy support, which require their own environment variables (prefixed with `GLOBAL_AGENT_`). This allows you to route the CLI’s network traffic through a proxy server, which can be useful in environments with restricted internet access.
 
-Additionally, yarn needs a proxy too (sometimes), when in environments with restricted internet access. It uses different settings than the other modules. If you decide to use the backstage yarn plugin [mentioned above](#plugin), you will need to set additional proxy values.
+Additionally, yarn needs a proxy too (sometimes), when in environments with restricted internet access. It uses different settings than the other modules. If you decide to use the backstage yarn plugin [mentioned above](#managing-package-versions-with-the-backstage-yarn-plugin), you will need to set additional proxy values.
 If you will always need proxy settings in all environments and situations, you can add `httpProxy` and `httpsProxy` values to [the yarnrc.yml file](https://yarnpkg.com/configuration/yarnrc). If some environments need it (say a developer workstation) but other environments do not (perhaps a CI build server running on AWS), then you may not want to update the yarnrc.yml file but just set environment variables `YARN_HTTP_PROXY` and `YARN_HTTPS_PROXY` in the environments/situations where you need to proxy.
 
 **If you plan to use the backstage yarn plugin, you will need these extra yarn proxy settings to both install the plugin and run the `versions:bump` command**. If you do not plan to use the backstage yarn plugin, it seems like the proxy settings alone are sufficient.

docs/getting-started/viewing-catalog.md

@@ -27,7 +27,7 @@ Initially, the Catalog displays registered entities matching the following filte
 - `Kind` - Component
 - `Type` - all
 - `Owner` - Owned
-- `Lifecycle` - list of [lifecycle](../features/software-catalog/descriptor-format.md#speclifecycle-required-1) values of entities in the Catalog
+- `Lifecycle` - list of [lifecycle](../features/software-catalog/descriptor-format.md#speclifecycle-required) values of entities in the Catalog
 - `Processing Status` - normal
 - `Namespace` - The ID of a [namespace](../features/software-catalog/descriptor-format.md#namespace-optional) to which the entity belongs