feat(startup): name an Edge blocker instead of hanging

Confirmed on the machine that started this: an 'Edge blocker' utility was
in the way, and unblocking Edge fixed the launch.

Those tools work by registering a Debugger entry under Image File
Execution Options for msedge.exe and msedgewebview2.exe, so Windows
refuses to run the process. The runtime is installed and registers its
version quite happily — which is why the logs showed WebView2 present —
and then never starts. OpsLog draws its whole interface with that engine,
so the window never opened: no error, no crash, a process sitting there
doing nothing.

That entry is read at startup now and said plainly, in the log and on
screen, with the one thing that helps: unblock Edge in the tool that
blocked it. Reinstalling OpsLog cannot fix a machine in this state, and
that is where an unexplained silence sends people.

Also logs the Windows build and which Edge policies are set — value names
only, never their contents: a policy key holds URLs and account names
that are nobody's business here.

main.go

@@ -165,6 +165,14 @@ func main() {
 	}()
 	noteLaunchAttempt()
 	bootLog("Windows %s", windowsVersion())
+	bootLog("Edge policy: %s", edgePolicyNotes())
+	// The blocker utilities: they leave an IFEO entry that makes Windows refuse
+	// to run the WebView2 process at all. Named loudly, because a machine in
+	// this state looks identical to one with a broken graphics driver.
+	if blocked := edgeExecutionBlocked(); blocked != "" {
+		bootLog("EDGE EXECUTION IS BLOCKED: %s — an \"Edge blocker\" tool is stopping WebView2 from starting", blocked)
+		fatalBox("OpsLog", edgeBlockedMessage)
+	}
 	bootLog("WebView2 profile: %q", webviewDataPath())
 	bootLog("entering wails.Run (window %dx%d, state %v)", width, height, startState)
 	err := wails.Run(&options.App{