Add native self-hosted instance connection to fluxer_desktop

Trimmed monorepo checkout (fluxer_desktop + packages/voice_engine_v2 +
tools/ci) with a "Connect to a Different Server" menu item and popout
that lets the desktop app switch to any self-hosted Fluxer instance,
plus fixes for well-known discovery on single-domain self-hosted
deployments and a false-positive ERR_ABORTED on same-origin client
redirects during the switch. Defaults to chat.fluxr.chat and uses an
isolated userData directory from the official build.

packages/voice_engine_v2/fixtures/event_logs/diagnostics_lifecycle.json

@@ -0,0 +1,51 @@
+{
+	"name": "diagnostics_lifecycle",
+	"events": [
+		{
+			"type": "diagnostics.logRequested",
+			"entry": {
+				"id": "diag-1",
+				"atMs": 1000,
+				"level": "info",
+				"code": "voice.session.started",
+				"message": "Voice session started"
+			}
+		},
+		{"type": "command.succeeded", "operationId": 1, "commandType": "diagnostics.log"},
+		{
+			"type": "diagnostics.logged",
+			"operationId": null,
+			"entry": {
+				"id": "diag-2",
+				"atMs": 1010,
+				"level": "warn",
+				"code": "voice.stats.delayed",
+				"message": "Stats collection was delayed",
+				"detail": {"delayMs": 250}
+			}
+		}
+	],
+	"expectedCommands": [
+		[
+			{
+				"type": "diagnostics.log",
+				"operationId": 1,
+				"entry": {
+					"id": "diag-1",
+					"atMs": 1000,
+					"level": "info",
+					"code": "voice.session.started",
+					"message": "Voice session started"
+				}
+			}
+		],
+		[],
+		[]
+	],
+	"expected": {
+		"nextOperationId": 2,
+		"entryIds": ["diag-1", "diag-2"],
+		"lastCode": "voice.stats.delayed",
+		"operationStatuses": {"1": "succeeded"}
+	}
+}