fix(docs): repoint 7 broken external and anchor links (DOCS-415) (#26572)

Closes [DOCS-415](https://linear.app/codercom/issue/DOCS-415).

## TL;DR

Repoints 7 broken links across 5 docs files that the 2026-06-22 weekly
`check-docs.yml` Linkspector run flagged. Two other links from the same
run (the dead `nix` ref and the dead `reflectoring.io` ref in
`CONTRIBUTING.md`) were already folded into
[#26341](https://github.com/coder/coder/pull/26341).

## Why

Broken external and anchor links degrade reader trust, leak SEO juice,
and make the docs look stale. The weekly `check-docs` job exists
precisely to catch this kind of rot before customers do; the
surfacing-to-fix turnaround on these 7 is one PR. Run that surfaced
them: [actions/runs/27948011619 job
82697664858](https://github.com/coder/coder/actions/runs/27948011619/job/82697664858).

## Scope

| File | Line(s) | Old target | New target | Why |
|------|---------|-----------|------------|-----|
| `docs/tutorials/best-practices/organizations.md` | 62 | anchor
`#update-template-metadata-by-id` | `#update-template-settings-by-id` |
API endpoint renamed in
[#19228](https://github.com/coder/coder/pull/19228) (Aug 2025). New
heading at line 1105 of `docs/reference/api/templates.md`. |
| `docs/install/registry-mirror-artifactory.md` | 197 | JFrog
`terraform-registry` |
`terraform-opentofu-and-terraform-backend-repositories` | JFrog
consolidated their Terraform / OpenTofu / Backend docs into a single
page. |
| `docs/admin/templates/extending-templates/modules.md` | 76, 206 |
JFrog `set-up-a-terraform-module/provider-registry` and
`terraform-registry` | same consolidated JFrog page (root, no anchor) |
Same JFrog consolidation. Anchor dropped, see decision log. |
| `docs/admin/integrations/dx-data-cloud.md` | 84 |
`https://help.getdx.com/en/` | `https://docs.getdx.com/` | DX migrated
their help center to a separate docs domain. |
| `docs/about/contributing/frontend.md` | 37, 71 |
`https://reactrouter.com/en/main` | `https://reactrouter.com/` | React
Router dropped the `/en/main` prefix. |

## Validation

- All 7 replacement URLs return HTTP 200 (manual `curl -L -o /dev/null
-w '%{http_code}'` per URL; linkspector's puppeteer crashed in the agent
env, so it was run case-by-case)
- `make lint/markdown lint/emdash` clean locally
- Pre-commit hook (`scripts/githooks/pre-commit` -> `make
pre-commit-light`) clean
- No `/docs/` route changes; pure markdown content

## Not triggering `/coder-agents-review`

Docs-only markdown edit, no CI or build config changes; per `AGENTS.md`
the bot review is reserved for product / CI changes. `doc-check` handles
this category.

## Pre-mortem

| Concern | Mitigation |
|---|---|
| Replacement URL also turns out to be broken later | All 7 verified
HTTP 200 today; next weekly `check-docs` run will catch any future
regression. |
| JFrog anchor drop on `modules.md` (76, 206) loses navigation context |
Verified the consolidated JFrog page has no clean section anchor for the
original target; linking the root page is the honest fix. If JFrog ships
a better TOC anchor later, a follow-up can reattach. |
| Anchor rename in `organizations.md` was actually a different rename |
Confirmed via PR #19228 (Aug 2025) which is the exact rename that
produced `## Update template settings by ID`. |

<details>
<summary>Decision log</summary>

**Why drop the anchor on the JFrog `modules.md` links (76 + 206)**:
JFrog's new consolidated page
(`/terraform-opentofu-and-terraform-backend-repositories`) doesn't
expose the original `set-up-a-terraform-module/provider-registry`
section as a fragment-link target. The honest fix is to link the page
root; readers can scroll. The `registry-mirror-artifactory.md:197`
reference uses the same root link for symmetry.

**Why DX `docs.getdx.com` over `help.getdx.com`**: DX's help center at
`help.getdx.com/en/` now returns 404. They moved to a separate
`docs.getdx.com` domain with a different content structure. Linking the
docs root is the closest analog to the original "browse our docs"
intent.

**Why React Router root over `/en/main`**: React Router unified their
docs under the root URL. The `/en/main` prefix is no longer routable.
The root URL is the canonical successor.

</details>


<details>
<summary>CI: <code>audit-docs-paths</code> failure (pre-existing,
unrelated)</summary>

The `audit-docs-paths` job in `.github/workflows/weekly-docs.yaml` fails
on this PR because its `Fetch redirects.json` step issues an
unauthenticated `curl` to a file in private `coder/coder.com` and gets a
404 (exit code 22). Same failure on every recent PR in this repo.
Tracked in [DOCS-409](https://linear.app/codercom/issue/DOCS-409) and
fixed in [#26571](https://github.com/coder/coder/pull/26571), which
authenticates the fetch through the Contents API. My changes are
docs-content only (5 markdown files, 7 line changes) and don't touch the
TS/TSX paths or `redirects.json` that the audit examines, so this is a
pre-existing CI break, not a regression introduced here.

</details>

---

*Generated by Coder Agents on @nickvigilante's behalf.*

docs/about/contributing/frontend.md

@@ -34,7 +34,7 @@ the most important.
 - [React](https://reactjs.org/) for the UI framework
 - [Typescript](https://www.typescriptlang.org/) to keep our sanity
 - [Vite](https://vitejs.dev/) to build the project
-- [react-router](https://reactrouter.com/en/main) for routing
+- [react-router](https://reactrouter.com/) for routing
 - [TanStack Query](https://tanstack.com/query/v4/docs/react/overview) for
   fetching data
 - [Vitest](https://vitest.dev/) for integration testing
@@ -68,7 +68,7 @@ the value.
 
 ## Routing
 
-We use [react-router](https://reactrouter.com/en/main) as our routing engine.
+We use [react-router](https://reactrouter.com/) as our routing engine.
 
 - Authenticated routes - Place routes requiring authentication inside the
   `<RequireAuth>` route. The `RequireAuth` component handles all the

docs/admin/integrations/dx-data-cloud.md

@@ -81,7 +81,7 @@ After the attribute is uploaded, you'll have a Coder filter option within your D
 
 ## Related Resources
 
-- [DX Data Cloud Documentation](https://help.getdx.com/en/)
+- [DX Data Cloud Documentation](https://docs.getdx.com/)
 - [Coder CLI](../../reference/cli/users.md)
 - [Coder API](../../reference/api/users.md)
 - [PlatformX Integration](./platformx.md)

docs/admin/templates/extending-templates/modules.md

@@ -73,7 +73,7 @@ for complete setup instructions.
 
 Air-gapped users can clone the [coder/registry](https://github.com/coder/registry/)
 repo and publish a
-[local terraform module repository](https://jfrog.com/help/r/jfrog-artifactory-documentation/set-up-a-terraform-module/provider-registry)
+[local terraform module repository](https://jfrog.com/help/r/jfrog-artifactory-documentation/terraform-opentofu-and-terraform-backend-repositories)
 to resolve modules via [Artifactory](https://jfrog.com/artifactory/).
 
 1. Create a local-terraform-repository with name `coder-modules-local`
@@ -203,6 +203,6 @@ coder:
 ### Next steps
 
 - JFrog's
-  [Terraform Registry support](https://jfrog.com/help/r/jfrog-artifactory-documentation/terraform-registry)
+  [Terraform Registry support](https://jfrog.com/help/r/jfrog-artifactory-documentation/terraform-opentofu-and-terraform-backend-repositories)
 - [Configuring the JFrog toolchain inside a workspace](../../integrations/jfrog-artifactory.md)
 - [Coder Module Registry](https://registry.coder.com/modules)

docs/install/registry-mirror-artifactory.md

@@ -194,5 +194,5 @@ Ensure the remote repository URL is set to `https://registry.coder.com` and not
 ## Next Steps
 
 - [Coder Module Registry](https://registry.coder.com/modules)
-- [JFrog Terraform Registry Documentation](https://jfrog.com/help/r/jfrog-artifactory-documentation/terraform-registry)
+- [JFrog Terraform Registry Documentation](https://jfrog.com/help/r/jfrog-artifactory-documentation/terraform-opentofu-and-terraform-backend-repositories)
 - [Air-gapped Deployments](./airgap.md)

docs/tutorials/best-practices/organizations.md

@@ -59,7 +59,7 @@ use organizations for several use cases.
 
 Since templates and workspaces cannot be moved nor can they belong to multiple
 organizations, we recommend that you deprecate your template
-[through the API](../../reference/api/templates.md#update-template-metadata-by-id)
+[through the API](../../reference/api/templates.md#update-template-settings-by-id)
 or [through the Coder CLI](../../reference/cli/templates_edit.md#--deprecated).
 When a template is deprecated, the admin prevents new workspaces from being
 created and developers are notified with a deprecation message which can link to