fix(installer): improve error message when port 4000 is already in use

Replace .unwrap() on TcpListener::bind with .with_context() so users
see a clear message about the port conflict instead of a panic.

Fixes #906

doc/configuration.md

@@ -61,12 +61,6 @@ On the first detection of a crash, a diagnostic snapshot is saved to `/data/rayh
 
 If recovery fails after 5 attempts, the status will change to **failed**. A reboot of the device will reset WiFi.
 
-You can also configure WiFi during installation:
-
-```sh
-./installer orbic --admin-password 'mypassword' --wifi-ssid 'MyNetwork' --wifi-password 'networkpass'
-```
-
 ## WebDAV Upload
 
 Rayhunter can automatically upload finished recordings to a WebDAV server. When a `[webdav]` section is present in `config.toml`, a background worker periodically scans the recording store and uploads any closed entry that is older than `min_age_secs`. Each eligible entry uploads two files: the raw `.qmdl` capture and its `.ndjson` analysis output. After a successful upload the entry is either marked as uploaded in the manifest (and skipped on subsequent polls), or deleted locally if `delete_on_upload = true`. With no `[webdav]` section, no upload worker runs.

installer/src/tplink.rs

@@ -346,9 +346,13 @@ async fn tplink_launch_telnet_v5(admin_ip: &str) -> Result<(), Error> {
             admin_ip: admin_ip.to_owned(),
         });
 
-    let listener = tokio::net::TcpListener::bind("127.0.0.1:4000")
+    let bind_addr = "127.0.0.1:4000";
+    let listener = tokio::net::TcpListener::bind(bind_addr)
         .await
-        .unwrap();
+        .with_context(|| format!(
+            "Failed to bind to {bind_addr}. Is another process using this port?\n\
+             Try closing any application that might be listening on port 4000 and rerun the installer."
+        ))?;
 
     println!("Listening on http://{}", listener.local_addr().unwrap());
     println!("Please open above URL in your browser and log into the router to continue.");