revert: remove fork-only changes from release sync

Revert payment/wechat, sora/claude-max cleanup, fork-only migrations,
and cosmetic changes that were brought in by the release sync commit.
Keep only channel-monitor related improvements:
- PublicSettingsInjectionPayload named struct with drift test
- ChannelMonitorRunner graceful shutdown in wire
- image_output_price in SupportedModelChip
- Simplified buildSelfNavItems in AppSidebar
- Gateway WARN logs for 503 branches

backend/internal/service/error_passthrough_runtime_test.go

@@ -220,7 +220,7 @@ func TestApplyErrorPassthroughRule_SkipMonitoringSetsContextKey(t *testing.T) {
 	v, exists := c.Get(OpsSkipPassthroughKey)
 	assert.True(t, exists, "OpsSkipPassthroughKey should be set when skip_monitoring=true")
 	boolVal, ok := v.(bool)
-	assert.True(t, ok, "value should be a bool")
+	assert.True(t, ok, "value should be bool")
 	assert.True(t, boolVal)
 }