feat(sync): Windows machines work as sync remotes

Remote temp dirs are now created and removed by the remote SubMiner
itself (sync --make-temp / --remove-temp, validated against its own
tmpdir) instead of mktemp/rm, and the flow detects the remote shell
(POSIX, cmd, PowerShell) to pick quoting and SubMiner install-location
candidates - %LOCALAPPDATA% app install, launcher shim, or PATH - with
no POSIX PATH prefix on Windows. Remote temp paths are normalized to
forward slashes for scp and the CLI. Verified end-to-end against a
throwaway sshd with the app binary as the resolved remote command.

launcher/config/args-normalizer.test.ts

@@ -145,6 +145,8 @@ test('applyInvocationsToArgs maps config and jellyfin invocation state', () => {
     syncForce: false,
     syncJson: false,
     syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
     syncLogLevel: null,
     syncUiTriggered: false,
     syncUiLogLevel: null,
@@ -204,6 +206,8 @@ test('applyInvocationsToArgs maps settings invocation to settings window', () =>
     syncForce: false,
     syncJson: false,
     syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
     syncLogLevel: null,
     syncUiTriggered: false,
     syncUiLogLevel: null,
@@ -256,6 +260,8 @@ test('applyInvocationsToArgs fails when config invocation has no action', () =>
       syncForce: false,
       syncJson: false,
       syncCheck: false,
+      syncMakeTemp: false,
+      syncRemoveTempPath: '',
       syncLogLevel: null,
       syncUiTriggered: false,
       syncUiLogLevel: null,
@@ -306,6 +312,8 @@ test('applyInvocationsToArgs maps texthooker browser-open request', () => {
     syncForce: false,
     syncJson: false,
     syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
     syncLogLevel: null,
     syncUiTriggered: false,
     syncUiLogLevel: null,