feat(settings): unified server-URL resolver + field; adopt in Jellyseerr

Type a loose address (media.example.com, https://…, host:port) and the app finds the working, canonical URL.

- utils/serverUrl: generic candidate generator (https-first, port/path preserved, no Jellyfin-specific ports), parallel-probe resolver, numeric semver compare, and a Jellyseerr probe (/api/v1/status, min 2.0.0).

- useServerUrlResolver: idle -> resolving -> ok | error state machine with cancellation.

- ServerUrlField: shared input that auto-resolves on blur, inline status chip (tap to re-test) + resolved URL, persists the canonical URL.

- Jellyseerr settings adopt the field and log in with the resolved URL. Probe contract makes Streamystats/Jellyfin/Merlin a drop-in follow-up.

utils/serverUrl/resolve.ts

@@ -0,0 +1,94 @@
+import { getServerUrlCandidates } from "./candidates";
+import type { ServerProbe, ServerProbeOutcome } from "./types";
+
+export type ResolveFailureReason =
+  | "empty"
+  | "invalid"
+  | "version-too-low"
+  | "wrong-service"
+  | "unreachable";
+
+export type ResolveResult =
+  | { ok: true; url: string; meta?: Record<string, unknown> }
+  | { ok: false; reason: ResolveFailureReason; version?: string };
+
+export interface ResolveOptions {
+  /** Per-candidate probe timeout in ms. Default 5000. */
+  timeoutMs?: number;
+  /** Abort the whole resolution (cancels every in-flight probe). */
+  signal?: AbortSignal;
+}
+
+// Order in which to surface a failure when no candidate validated:
+// the more specific/actionable the reason, the earlier it is reported.
+const FAILURE_PRIORITY = [
+  "version-too-low",
+  "wrong-service",
+  "unreachable",
+] as const satisfies ReadonlyArray<ResolveFailureReason>;
+
+/**
+ * Resolve loose user input to a single working, canonical server URL.
+ *
+ * Generates candidates (https-first), probes them in parallel with a per-candidate
+ * timeout, and returns the first candidate (in preference order) the probe
+ * accepted. When none work, the most actionable failure is returned.
+ */
+export async function resolveServerUrl(
+  input: string,
+  probe: ServerProbe,
+  options: ResolveOptions = {},
+): Promise<ResolveResult> {
+  const { timeoutMs = 5000, signal } = options;
+
+  if (!input.trim()) return { ok: false, reason: "empty" };
+
+  const candidates = getServerUrlCandidates(input);
+  if (candidates.length === 0) return { ok: false, reason: "invalid" };
+
+  const outcomes = await Promise.all(
+    candidates.map((url) => runProbe(url, probe, timeoutMs, signal)),
+  );
+
+  // Prefer the first candidate (https-first) that validated.
+  for (let i = 0; i < candidates.length; i++) {
+    const outcome = outcomes[i];
+    if (outcome.status === "ok") {
+      return { ok: true, url: candidates[i], meta: outcome.meta };
+    }
+  }
+
+  // Nothing validated: report the most useful failure.
+  for (const reason of FAILURE_PRIORITY) {
+    const hit = outcomes.find((outcome) => outcome.status === reason);
+    if (hit) {
+      return {
+        ok: false,
+        reason,
+        version: hit.status === "version-too-low" ? hit.version : undefined,
+      };
+    }
+  }
+  return { ok: false, reason: "unreachable" };
+}
+
+async function runProbe(
+  url: string,
+  probe: ServerProbe,
+  timeoutMs: number,
+  parentSignal?: AbortSignal,
+): Promise<ServerProbeOutcome> {
+  const controller = new AbortController();
+  const abort = () => controller.abort();
+  parentSignal?.addEventListener("abort", abort);
+  const timer = setTimeout(abort, timeoutMs);
+
+  try {
+    return await probe(url, controller.signal);
+  } catch {
+    return { status: "unreachable" };
+  } finally {
+    clearTimeout(timer);
+    parentSignal?.removeEventListener("abort", abort);
+  }
+}