fix(server): keep users' keys at their own endpoints, and more fixes from the third review

- Bedrock: a user's AWS keys no longer go to an endpoint the server sets
  in AWS_ENDPOINT_URL_BEDROCK_RUNTIME / AWS_ENDPOINT_URL (read by the
  upgraded SDK), and admin panel keys win over AWS_BEARER_TOKEN_BEDROCK,
  as the Test button checks them. Checked with Bedrock.
- Ollama: a server key without a base URL (admin panel, OLLAMA_API_KEY)
  goes to Ollama Cloud, as env.example says, instead of 127.0.0.1.
- Quota: EdgeOne counts whatever key header comes along, keyless Ollama at
  a private address counts, and their provider texts stay in the log.
- An EdgeOne server model (admin panel, ai-models.json) works: the route
  checked the raw provider header, which holds the name's slug.
- parse-url ends downloads it does not read (too large, PDF, errors).
- Desktop app: the port follows where the chats are (IndexedDB per
  origin) instead of a remembered port, which could hide them for good;
  a same-port restart tells the page to refetch the server models; a
  failed preset switch no longer undoes a newer choice; a presets file
  removed after a failed read can be saved again; .env values quoted from
  start to end keep their inner quotes, as dotenv reads them.

electron/preload/index.ts

@@ -27,4 +27,13 @@ contextBridge.exposeInMainWorld("electronAPI", {
     getUserLocale: () => ipcRenderer.invoke("get-user-locale"),
     setUserLocale: (locale: string) =>
         ipcRenderer.invoke("set-user-locale", locale),
+
+    // The server restarted on the same port (another preset)
+    onServerRestarted: (callback: () => void) => {
+        const listener = () => callback()
+        ipcRenderer.on("server-restarted", listener)
+        return () => {
+            ipcRenderer.removeListener("server-restarted", listener)
+        }
+    },
 })