refactor(settings): remove dead machine path fields from frontend

Slice 2 of jellyfin-service-registry. Removes the machine-level
media_root/path_prefix fields from the frontend now that the backend no
longer stores them.

- types/index.ts: dropped media_root/path_prefix from MonitoringMachine
  and MonitoringMachineInput.
- pages/Settings.tsx: removed the media_root form input, the read-only
  "Media root" detail (replaced with a local-hint field mirroring the
  editor), and media_root/path_prefix from emptyMachine() and both
  edit-handler reset mappings; updated the section description.
- tests: removed media_root/path_prefix from Settings/Media/FileBrowser
  test fixtures.

npm run build (tsc -b + vite) clean; 0 lint errors; 72 tests pass.

frontend/src/pages/Settings.tsx

@@ -122,8 +122,6 @@ function emptyMachine(
 		ssh_private_key: "",
 		ssh_private_key_passphrase: "",
 		password: "",
-		media_root: "",
-		path_prefix: "",
 		notes: "",
 	};
 }
@@ -373,22 +371,9 @@ function MachineEditor({
 					<div className="col-span-12">
 						<SectionLabel
 							title="Monitoring / Files"
-							description="Media root and path mapping used by monitoring and browsing. Saving a monitoring machine also starts its collector automatically."
+							description="Enable monitoring and file browsing for this machine."
 						/>
 					</div>
-					<div className="col-span-12 md:col-span-6">
-						<FormField label="Media root">
-							<Input
-								value={draft.media_root}
-								onChange={(e) =>
-									setDraft((current) => ({
-										...current,
-										media_root: e.target.value,
-									}))
-								}
-							/>
-						</FormField>
-					</div>
 					{isLocal && (
 						<div className="col-span-12 md:col-span-6">
 							<FormField label="Local hint">
@@ -1031,12 +1016,10 @@ export function Settings() {
 																username: machine.username,
 																key_directory: "",
 																key_name: "",
-																path_prefix: "",
 																ssh_key_id: machine.ssh_key_id,
 																ssh_private_key: "",
 																ssh_private_key_passphrase: "",
 																password: "",
-																media_root: machine.media_root,
 																notes: machine.notes,
 															},
 															machine,
@@ -1093,11 +1076,8 @@ export function Settings() {
 														</FormField>
 													</>
 												) : (
-													<FormField label="Media root">
-														<Input
-															value={selectedMachine.media_root || "localhost"}
-															disabled
-														/>
+													<FormField label="Local hint">
+														<Input value="Uses the API host directly" disabled />
 													</FormField>
 												)}
 											</div>
@@ -1117,12 +1097,10 @@ export function Settings() {
 																username: selectedMachine.username,
 																key_directory: "",
 																key_name: "",
-																path_prefix: "",
 																ssh_key_id: selectedMachine.ssh_key_id,
 																ssh_private_key: "",
 																ssh_private_key_passphrase: "",
 																password: "",
-																media_root: selectedMachine.media_root,
 																notes: selectedMachine.notes,
 															},
 															selectedMachine,

frontend/src/pages/__tests__/FileBrowser.test.tsx

@@ -28,8 +28,6 @@ function machineFixture(
 		ssh_private_key_set: false,
 		ssh_private_key_passphrase_set: false,
 		password_set: false,
-		media_root: "",
-		path_prefix: "",
 		notes: "",
 		...overrides,
 	};

frontend/src/pages/__tests__/Media.test.tsx

@@ -32,8 +32,6 @@ function machineFixture(
 		ssh_private_key_set: false,
 		ssh_private_key_passphrase_set: false,
 		password_set: false,
-		media_root: "",
-		path_prefix: "",
 		notes: "",
 		...overrides,
 	};

frontend/src/pages/__tests__/Settings.test.tsx

@@ -51,8 +51,6 @@ function localMachine(
 		ssh_private_key_set: false,
 		ssh_private_key_passphrase_set: false,
 		password_set: false,
-		media_root: "/mnt/media",
-		path_prefix: "",
 		notes: "Primary node",
 		...overrides,
 	} as MonitoringMachine;

frontend/src/types/index.ts

@@ -170,8 +170,6 @@ export interface MonitoringMachine {
 	ssh_private_key_set: boolean;
 	ssh_private_key_passphrase_set: boolean;
 	password_set: boolean;
-	media_root: string;
-	path_prefix: string;
 	notes: string;
 }
 
@@ -190,8 +188,6 @@ export interface MonitoringMachineInput {
 	ssh_private_key: string;
 	ssh_private_key_passphrase: string;
 	password: string;
-	media_root: string;
-	path_prefix: string;
 	notes: string;
 }