docs: improve first-stream tutorial with XS_ADDR setup instructions

Add clear prerequisites and a prominent callout explaining that XS_ADDR
must be set when using a non-default store path. Also simplify xs-addr
resolution by removing broken config file logic.

Author: cablehead

docs/src/content/docs/getting-started/first-stream.mdx

@@ -11,10 +11,13 @@ import { Link } from '../../../utils/links';
 
 Let's create your first event stream.
 
-<Aside>
-This tutorial uses commands from `xs.nu`. If you haven't installed it yet,
-run `xs nu --install` and then `use xs.nu *` in Nushell. See the
-[installation guide](../installation/) for details.
+<Aside type="tip" title="Prerequisites">
+Before starting, make sure you have:
+1. Run `xs nu --install` once to install the Nushell integration
+2. Started a new Nushell session (or run `use xs.nu *`)
+3. Have **two terminal windows** ready: one for the server, one for the client
+
+See the [installation guide](../installation/) for details.
 </Aside>
 
 ## Serve
@@ -36,7 +39,7 @@ Start an `xs` store in a dedicated window:
 ```
 
 For a long-running setup you might run `xs serve ~/.local/share/cross.stream/store`
-under a process supervisor. This is also the fallback location used by
+under a process supervisor. This is the default location used by
 `xs.nu` when `$env.XS_ADDR` isn't set. Here we keep the demo scoped to `./store`.
 
 To point tools at another store, set `XS_ADDR`. This can be done temporarily with `with-env`:
@@ -45,6 +48,19 @@ To point tools at another store, set `XS_ADDR`. This can be done temporarily wit
 with-env {XS_ADDR: "./store"} { .cat }
 ```
 
+<Aside type="caution" title="Set XS_ADDR for this tutorial">
+Since we're using `./store` instead of the default location, set `XS_ADDR`
+in your client terminal before running any commands:
+
+```nushell
+$env.XS_ADDR = (realpath ./store)
+```
+
+Without this, the client will try to connect to the default path
+(`~/.local/share/cross.stream/store`) and fail with a connection error
+(on Windows, this may appear as "dead network (os error 10050)").
+</Aside>
+
 ## Client
 
 ### `append` command

xs.nu

@@ -21,7 +21,7 @@ def conditional-pipe [
 }
 
 export def xs-addr [] {
-  $env | get XS_ADDR? | or-else { try { open ~/.config/cross.stream/XS_ADDR | str trim | path expand } } | or-else { "~/.local/share/cross.stream/store" | path expand }
+  $env | get XS_ADDR? | or-else { "~/.local/share/cross.stream/store" | path expand }
 }
 
 export def xs-context-collect [] {