docs: remove the multi-region page

Steel Cloud serves browsers from one region. The page listed LAX and IAD
as available data centers and used `region: "lax"` in every example, so
anyone following it got a 503 telling them to retry shortly, for capacity
that does not exist. No lax browser has run in at least 7 days.

Removes the page, its sidebar entry, the Steel Local vs Cloud comparison
row and the changelog link, and 301s the old URL to the Network identity
section of the configuration page.

That section was the only other place `region` appeared, and with the
table gone it no longer named a single valid value, so it now states the
one region Steel serves instead of presenting region as a choice.

Author: fukouda

content/docs/changelog/changelog-011.mdx

@@ -37,8 +37,6 @@ At Steel, we understand that latency kills agent performance, especially with hu
 
 We've expanded Steel Cloud to 7 global regions with automatic closest-region selection—from Los Angeles to Hong Kong, your browsers spin up wherever makes the most sense. Read the announcement thread here.
 
-[Read Multi-Region Docs →](/overview/sessions-api/multi-region)
-
 ### Day 4 - Filesystem V2
 
 <Image src="/images/cmbf90lm40gslym0i1arf4ivq.png" alt="Filesystem V2" width={800} height={500} />

content/docs/overview/self-hosting/steel-local-vs-steel-cloud.mdx

@@ -12,7 +12,6 @@ llm: true
 | Stealth          | Limited                                   | Advanced Stealth (docs)                                      |
 | CAPTCHA Solving  | None                                      | Supported with the CAPTCHAs API                              |
 | Proxies          | Bring your own                            | Bring your own + Steel Managed Proxies                       |
-| Multi-Region     | Host it yourself                          | Supported with region flag during session creation           |
 | Credentials      | Not supported                             | Supported with the Credentials API                           |
 | Extensions       | Supported by loading in `api/extensions/` | Supported by using the Extensions API                        |
 | Files            | Not supported                             | Supported by the Files API                                   |

content/docs/overview/sessions-api/configuration.mdx

@@ -1,7 +1,7 @@
 ---
 title: Configure a Browser Session
 sidebarTitle: Configure a Session
-description: Select Steel session settings for browser tasks, stored state, regional access, mobile sites, and human control.
+description: Select Steel session settings for browser tasks, stored state, mobile sites, and human control.
 llm: true
 ---
 
@@ -49,7 +49,6 @@ If you know the browser behavior that the task needs, use this table.
 | Use a residential IP | `useProxy: true` | [Network identity](#network-identity) |
 | Select the IP location | `useProxy.geolocation` | [Network identity](#network-identity) |
 | Use the same dedicated IP | `useProxy: { type: "fixed", id: "fixed:…" }` | [Network identity](#network-identity) |
-| Run the browser in a selected region | `region` | [Network identity](#network-identity) |
 | Load saved browser state | `profileId` | [Stored state](#stored-state) |
 | Save profile changes after release | `persistProfile: true` | [Stored state](#stored-state) |
 | Add cookies or web storage | `sessionContext` | [Stored state](#stored-state) |
@@ -238,15 +237,14 @@ Use the smallest location scope that the task needs.
 | Use one dedicated IP | Set `useProxy.type` to `fixed` and add the dedicated IP `id`. |
 | Use any active dedicated IP | Set `useProxy.type` to `fixed` and omit `id`. |
 | Use your proxy | Set `useProxy.server` or `proxyUrl`. |
-| Select the browser region | Set `region`. |
 
-- `region` selects the location of the browser process. Proxy geolocation selects the public IP
-  location that the site receives.
+- Steel runs browsers in one region, `us-east`. The `region` parameter is still accepted, and
+  any other value is rejected.
+- Proxy geolocation, not `region`, selects the public IP location that the site receives.
 - If you load a profile, `useProxy: false` overrides the proxy setting in that profile.
 - `proxyUrl` overrides `useProxy`. Use only one custom proxy method in a session request.
 
-See [Multi-Region Sessions](/overview/sessions-api/multi-region),
-[Proxies](/overview/stealth/proxies), and
+See [Proxies](/overview/stealth/proxies) and
 [Dedicated IPs](/overview/sessions-api/dedicated-ips).
 
 ### Stored state

content/docs/overview/sessions-api/meta.json

@@ -9,7 +9,6 @@
     "session-lifecycle",
     "mobile-mode",
     "fullscreen-mode",
-    "multi-region",
     "dedicated-ips",
     "embed-sessions",
     "human-in-the-loop",

content/docs/overview/sessions-api/multi-region.mdx

@@ -92,6 +92,13 @@ const config = {
         destination: "https://www.val.town/x/steel/steel_puppeteer_starter",
         permanent: true,
       },
+      // The multi-region page is retired: Steel serves browsers from one
+      // region, so `region` is documented with the other session settings.
+      {
+        source: "/overview/sessions-api/multi-region",
+        destination: "/overview/sessions-api/configuration#network-identity",
+        permanent: true,
+      },
       // Legacy cookbook URLs. Concept pages now merge language variants via
       // a hash-driven Fumadocs Tabs component, so old language-suffixed
       // slugs redirect to `/cookbook/<concept>#<lang>`.