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/main/env-loader.ts

@@ -51,7 +51,11 @@ function loadEnvFromFile(filePath: string): void {
             const quote = value[0]
             const closingQuote =
                 quote === '"' || quote === "'" ? value.indexOf(quote, 1) : -1
-            if (closingQuote > 0) {
+            if (value.length > 1 && value.endsWith(quote) && closingQuote > 0) {
+                // Quoted from start to end: the quotes inside belong to the
+                // value (JSON with an apostrophe), as dotenv reads it
+                value = value.slice(1, -1)
+            } else if (closingQuote > 0) {
                 // Quoted value: keep what's inside the quotes and drop
                 // anything after them (e.g. a comment)
                 value = value.slice(1, closingQuote)