fix(wallet): reliable process detection + drop the harmful start-retry

Two issues the latest live log exposed:
- The switch's start-retry spawned a SECOND dragonxd while the first was still
  shutting down, so the two held wallet.dat against each other (BDB "Failed to
  rename wallet-savings.dat … Error"), and it then span on a stale "Daemon
  already running". Revert to a single start — the stopDaemonForWalletSwitch()
  wait already ensures the old process is gone, so a valid wallet opens cleanly
  and a bad one exits during init and reverts, without overlapping spawns.
- findProcessByName() used the non-suffixed PROCESSENTRY32/Process32First with an
  ANSI _stricmp; if UNICODE is defined those map to the wide variants, so the
  compare comparing garbage would NEVER match — silently making the process-gone
  wait a no-op. Rewritten with the explicit wide Toolhelp API + lstrcmpiW so it's
  correct either way (verified to compile under mingw with and without -DUNICODE).

Note: a corrupt wallet.dat (BDB recovery failing) still can't be opened by any
node — that's a data issue needing a clean reset, not a switch-flow bug.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/daemon/embedded_daemon.cpp

@@ -683,18 +683,25 @@ static DWORD findProcessByName(const char* name)
 {
     HANDLE snap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
     if (snap == INVALID_HANDLE_VALUE) return 0;
-    
-    PROCESSENTRY32 entry;
+
+    // Use the explicit WIDE Toolhelp API + a wide compare so this is correct regardless of the UNICODE
+    // macro. (The non-suffixed PROCESSENTRY32/Process32First map to the wide variants when UNICODE is
+    // defined, in which case szExeFile is WCHAR[] and an ANSI _stricmp would compare garbage and NEVER
+    // match — silently making findProcessByName a no-op that returns 0 for a running process.)
+    wchar_t wname[MAX_PATH];
+    if (MultiByteToWideChar(CP_ACP, 0, name, -1, wname, MAX_PATH) == 0) { CloseHandle(snap); return 0; }
+
+    PROCESSENTRY32W entry;
     entry.dwSize = sizeof(entry);
-    
+
     DWORD pid = 0;
-    if (Process32First(snap, &entry)) {
+    if (Process32FirstW(snap, &entry)) {
         do {
-            if (_stricmp(entry.szExeFile, name) == 0) {
+            if (lstrcmpiW(entry.szExeFile, wname) == 0) {   // Win32 case-insensitive wide compare
                 pid = entry.th32ProcessID;
                 break;
             }
-        } while (Process32Next(snap, &entry));
+        } while (Process32NextW(snap, &entry));
     }
     CloseHandle(snap);
     return pid;